<SUBMISSION>
<ACCESSION-NUMBER>0000912057-01-515977
<TYPE>10-Q
<PUBLIC-DOCUMENT-COUNT>3
<PERIOD>20010331
<FILING-DATE>20010515
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>IRON MOUNTAIN INC/PA
<CIK>0001020569
<ASSIGNED-SIC>4220
<IRS-NUMBER>232588479
<STATE-OF-INCORPORATION>PA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>10-Q
<ACT>34
<FILE-NUMBER>001-13045
<FILM-NUMBER>1637957
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>745 ATLANTIC AVENUE
<CITY>BOSTON
<STATE>MA
<ZIP>02111-
<PHONE>6175354766
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>745 ATLANTIC AVENUE
<CITY>BOSTON
<STATE>MA
<ZIP>02111-
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>PIERCE LEAHY CORP
<DATE-CHANGED>19960807
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>10-Q
<SEQUENCE>1
<FILENAME>a2049379z10-q.txt
<DESCRIPTION>FORM 10-Q
<TEXT>

<PAGE>
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                            ------------------------

                                   FORM 10-Q

(MARK ONE)

<TABLE>
<C>        <S>
   /X/     QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
           SECURITIES EXCHANGE ACT OF 1934
</TABLE>

                 FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2001
                                       OR

<TABLE>
<C>        <S>
   / /     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
           SECURITIES EXCHANGE ACT OF 1934
</TABLE>

        FOR THE TRANSITION PERIOD FROM ______________ TO ______________

                         COMMISSION FILE NUMBER 1-13045

                            ------------------------

                           IRON MOUNTAIN INCORPORATED

             (Exact Name of Registrant as Specified in its Charter)

<TABLE>
<S>                                    <C>
            PENNSYLVANIA                            23-2588479
   (State or Other Jurisdiction of       (IRS Employer Identification No.)
   Incorporation or Organization)
</TABLE>

                     745 ATLANTIC AVENUE, BOSTON, MA 02111
          (Address of Principal Executive Offices, Including Zip Code)

                                 (617) 535-4766
              (Registrant's Telephone Number, Including Area Code)

                            ------------------------

    Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

    Yes /X/  No / /

    Number of shares of the registrant's Common Stock outstanding as of May 4,
2001: 55,579,027

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
                           IRON MOUNTAIN INCORPORATED
                                     INDEX

<TABLE>
<CAPTION>
                                                                             PAGE
                                                                           --------
<S>         <C>                                                            <C>
PART I--FINANCIAL INFORMATION

Item 1--    Unaudited Condensed Consolidated Financial Statements

            Condensed Consolidated Balance Sheets at March 31, 2001 and
            December 31, 2000 (Unaudited)...............................        3

            Condensed Consolidated Statements of Operations for the
            Three Months Ended March 31, 2001 and 2000 (Unaudited)......        4

            Condensed Consolidated Statements of Cash Flows for the
            Three Months Ended March 31, 2001 and 2000 (Unaudited)......        5

            Notes to Condensed Consolidated Financial Statements
            (Unaudited).................................................     6-17

Item 2--    Management's Discussion and Analysis of Financial Condition
            and Results of Operations...................................    18-20

Item 3--    Quantitative and Qualitative Disclosures About Market
            Risk........................................................       21

PART II--OTHER INFORMATION

Item 6--    Exhibits and Reports on Form 8-K............................       21

            Signature...................................................       22
</TABLE>

                                       2
<PAGE>
PART I. FINANCIAL INFORMATION

ITEM 1. UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                           IRON MOUNTAIN INCORPORATED

                     CONDENSED CONSOLIDATED BALANCE SHEETS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                              MARCH 31,    DECEMBER 31,
                                                                 2001          2000
                                                              ----------   ------------
<S>                                                           <C>          <C>
ASSETS
Current Assets:
  Cash and cash equivalents.................................  $    9,903    $    6,200
  Accounts receivable (less allowances of $17,786 and
    $15,989 respectively)...................................     208,057       176,442
  Deferred income taxes.....................................      31,128        30,990
  Prepaid expenses and other................................      27,690        23,036
                                                              ----------    ----------
      Total Current Assets..................................     276,778       236,668
Property, Plant and Equipment:
  Property, plant and equipment.............................   1,033,895       984,939
  Less: Accumulated depreciation............................    (172,592)     (152,545)
                                                              ----------    ----------
      Property, Plant and Equipment, net....................     861,303       832,394
Other Assets, net:
  Goodwill..................................................   1,535,901     1,525,630
  Customer acquisition costs................................      29,167        27,692
  Deferred financing costs..................................      14,137        14,534
  Other.....................................................      20,768        22,178
                                                              ----------    ----------
      Total Other Assets, net...............................   1,599,973     1,590,034
                                                              ----------    ----------
      Total Assets..........................................  $2,738,054    $2,659,096
                                                              ==========    ==========

LIABILITIES AND SHAREHOLDERS' EQUITY

Current Liabilities:
  Current portion of long-term debt.........................  $   31,629    $   40,789
  Accounts payable..........................................      37,831        42,531
  Accrued expenses..........................................     146,488       153,291
  Deferred income...........................................      76,729        53,884
  Other current liabilities.................................      17,129        23,558
                                                              ----------    ----------
      Total Current Liabilities.............................     309,806       314,053
Long-term Debt, net of current portion......................   1,371,442     1,314,342
Other Long-term Liabilities.................................      12,095         7,920
Deferred Rent...............................................      16,731        16,346
Deferred Income Taxes.......................................      32,773        38,948
Minority Interest...........................................      69,272        43,029
Shareholders' Equity:
  Common stock..............................................         555           553
  Additional paid-in capital................................     994,427       990,854
  Accumulated deficit.......................................     (56,439)      (59,383)
  Accumulated other comprehensive items.....................     (12,608)       (7,566)
                                                              ----------    ----------
      Total Shareholders' Equity............................     925,935       924,458
                                                              ----------    ----------
      Total Liabilities and Shareholders' Equity............  $2,738,054    $2,659,096
                                                              ==========    ==========
</TABLE>

  THE ACCOMPANYING NOTES ARE AN INTEGRAL PART OF THESE CONSOLIDATED FINANCIAL
                                  STATEMENTS.

                                       3
<PAGE>
                           IRON MOUNTAIN INCORPORATED

                CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

                     (IN THOUSANDS, EXCEPT PER SHARE DATA)

                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                              THREE MONTHS ENDED
                                                                   MARCH 31,
                                                              -------------------
                                                                2001       2000
                                                              --------   --------
<S>                                                           <C>        <C>
Revenues:
  Storage...................................................  $167,865   $124,939
  Service and storage material sales........................   116,057     87,198
                                                              --------   --------

      Total Revenues........................................   283,922    212,137

Operating Expenses:
  Cost of sales (excluding depreciation)....................   139,820    104,458
  Selling, general and administrative.......................    70,317     53,457
  Depreciation and amortization.............................    35,718     26,303
  Merger-related expenses...................................       801        516
                                                              --------   --------

      Total Operating Expenses..............................   246,656    184,734
                                                              --------   --------

Operating Income............................................    37,266     27,403

Interest Expense............................................    33,987     23,783
Other Expense...............................................    (9,187)      (781)
                                                              --------   --------

      Income (Loss) Before Provision (Benefit) for Income
        Taxes and Minority Interest.........................    (5,908)     2,839

Provision (Benefit) for Income Taxes........................    (8,837)     8,529
Minority Interest in Losses of Subsidiaries.................      (270)      (307)
                                                              --------   --------

Net Income (Loss)...........................................  $  3,199   $ (5,383)
                                                              ========   ========

Net Income (Loss) per Share -- Basic and Diluted............  $   0.06   $  (0.11)
                                                              --------   --------

Weighted Average Common Shares Outstanding--Basic...........    55,427     47,943
                                                              ========   ========
Weighted Average Common Shares Outstanding--Diluted.........    56,593     47,943
                                                              ========   ========
</TABLE>

  THE ACCOMPANYING NOTES ARE AN INTEGRAL PART OF THESE CONSOLIDATED FINANCIAL
                                  STATEMENTS.

                                       4
<PAGE>
                           IRON MOUNTAIN INCORPORATED

                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                               THREE MONTHS ENDED
                                                                    MARCH 31,
                                                              ---------------------
                                                                2001        2000
                                                              ---------   ---------
<S>                                                           <C>         <C>
Cash Flows from Operating Activities:
  Net Income (Loss).........................................   $ 3,199    $ (5,383)
  Adjustments to Reconcile Net Income (Loss) to Cash
    Provided by Operating Activities:
    Minority Interests in Losses of Subsidiaries............      (270)       (307)
    Depreciation and Amortization...........................    35,718      26,303
    Amortization of Deferred Financing Costs and Bond
      Discount..............................................       495         656
    Provision for Doubtful Accounts.........................     2,381       1,196
    Foreign Currency Loss...................................     9,187         781
    Other, Net..............................................       506         747
  Changes in Assets and Liabilities (Exclusive of
    Acquisitions):
    Accounts Receivable.....................................    (9,558)      1,068
    Prepaid Expenses and Other Current Assets...............    (7,375)      2,025
    Deferred Income Taxes...................................    (6,428)     10,447
    Other Assets............................................      (616)        298
    Accounts Payable........................................    (4,630)    (12,092)
    Accrued Expenses........................................     2,048     (10,261)
    Deferred Income.........................................      (739)     (1,016)
    Other Current Liabilities...............................       135          50
    Deferred Rent...........................................       391         481
    Other Long-term Liabilities.............................      (545)      2,725
                                                               -------    --------
      Cash Flows Provided by Operating Activities...........    23,899      17,718

Cash Flows from Investing Activities:
  Capital Expenditures......................................   (48,198)    (27,646)
  Cash Paid for Acquisitions, net of cash acquired..........   (34,773)     (5,636)
  Additions to Customer Acquisition Costs...................    (2,307)     (3,356)
  Other, Net................................................        29        (435)
                                                               -------    --------
      Cash Flows Used in Investing Activities...............   (85,249)    (37,073)

Cash Flows from Financing Activities:
  Repayment of Debt.........................................   (35,734)   (203,267)
  Proceeds from Borrowings..................................    82,355     223,558
  Debt Contribution from (Repayment to) Minority
    Shareholders............................................    (6,560)      7,036
  Equity Contributions from Minority Shareholders...........    24,529          --
  Proceeds from Exercise of Stock Options...................     2,539         885
  Financing and Stock Issuance Costs........................      (235)     (2,769)
                                                               -------    --------
      Cash Flows Provided by Financing Activities...........    66,894      25,443

Effect of Exchange Rates on Cash and Cash Equivalents.......    (1,841)        186
Increase in Cash and Cash Equivalents.......................     3,703       6,274
Cash and Cash Equivalents, Beginning of Period..............     6,200       3,830
                                                               -------    --------
Cash and Cash Equivalents, End of Period....................   $ 9,903    $ 10,104
                                                               =======    ========
</TABLE>

  THE ACCOMPANYING NOTES ARE AN INTEGRAL PART OF THESE CONSOLIDATED FINANCIAL
                                  STATEMENTS.

                                       5
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

(1) GENERAL

    The interim condensed consolidated financial statements presented herein
have been prepared by Iron Mountain Incorporated ("Iron Mountain" or the
"Company") without audit and, in the opinion of management, reflect all
adjustments of a normal recurring nature necessary for a fair presentation.
Interim results are not necessarily indicative of results for a full year.

    The condensed consolidated balance sheet presented as of December 31, 2000
has been derived from the consolidated financial statements that have been
audited by the Company's independent public accountants. The unaudited condensed
consolidated financial statements have been prepared pursuant to the rules and
regulations of the Securities and Exchange Commission. Certain information and
footnote disclosures normally included in the annual financial statements
prepared in accordance with generally accepted accounting principles have been
omitted pursuant to those rules and regulations, but the Company believes that
the disclosures are adequate to make the information presented not misleading.
The condensed consolidated financial statements and notes included herein should
be read in conjunction with the consolidated financial statements and notes
included in the Company's Annual Report on Form 10-K for the year ended
December 31, 2000.

    Certain reclassifications have been made to the 2000 financial statements to
conform to the 2001 presentation.

(2) COMPREHENSIVE LOSS

    Statement of Financial Accounting Standards ("SFAS") No. 130, "Reporting
Comprehensive Income," requires presentation of the components of comprehensive
income (loss), including the changes in equity from non-owner sources such as
unrealized gains (losses) on securities and foreign currency translation
adjustments. The Company's total comprehensive income (loss) is as follows:

<TABLE>
<CAPTION>
                                                  THREE MONTHS ENDED MARCH 31,
                                                  -----------------------------
                                                      2001            2000
                                                  -------------   -------------
<S>                                               <C>             <C>
Comprehensive Loss:
  Net Income (Loss).............................     $ 3,199         $(5,383)

Other Comprehensive Loss:
  Foreign Currency Translation Adjustment.......        (788)            121
  Transition Adjustment Charge..................        (214)             --
  Unrealized Loss on Hedging Contracts..........      (4,040)             --
                                                     -------         -------
Comprehensive Loss..............................     $(1,843)        $(5,262)
                                                     =======         =======
</TABLE>

                                       6
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(3) DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

    The Company adopted the provisions of SFAS No. 133, Accounting for
Derivative Instruments and Hedging Activities, on January 1, 2001. SFAS No. 133
requires that every derivative instrument be recorded in the balance sheet as
either an asset or a liability measured at its fair value. The adoption of SFAS
No. 133 on January 1, 2001 resulted in the recognition of a derivative liability
and a corresponding transition adjustment charge to accumulated other
comprehensive items of approximately $214.

    Periodically, the Company acquires derivative instruments that are intended
to hedge either cash flows or values which are subject to exchange or other
market price risk, and not for trading purposes. The Company has formally
documented its hedging relationships, including identification of the hedging
instruments and the hedge items, as well as its risk management objectives and
strategies for undertaking each hedge transaction.

    The Company has entered into three interest rate swap agreements, which are
derivatives as defined by SFAS No. 133 and designated as cash flow hedges. These
swap agreements hedge interest rate risk on certain amounts of its Tranche B
debt as well as certain variable operating lease commitments. For all qualifying
and highly effective cash flow hedges, the changes in the fair value of the
derivatives are recorded in other comprehensive income. As a result of these
interest rate swap agreements, the Company has recorded a derivative liability
of and a corresponding charge to accumulated other comprehensive items of
approximately $4,254 at March 31, 2001.

    During the period ending March 31, 2001, the Company recorded net losses of
$59 and $9 resulting from interest rate swap settlements in interest and rent
expense, respectively. All interest rate swap agreements were determined to be
highly effective whereby no ineffectiveness was recorded in earnings.

(4) ACQUISITIONS

    During the three months ended March 31, 2001, the Company purchased
substantially all of the assets, and assumed certain liabilities, of six records
and information management services businesses.

    Each of the 2001 acquisitions and all 12 of the records and information
management services businesses acquired during 2000 were accounted for using the
purchase method of accounting and, accordingly, the results of operations for
each acquisition have been included in the consolidated results of the Company
from their respective acquisition dates. In connection with certain 2001 and
2000 acquisitions, related real estate was also purchased. The aggregate
purchase price for the 2001 acquisitions exceeded the underlying fair value of
the net assets acquired by $29,255 which has been assigned to goodwill and is
being amortized over 25 to 30 years.

    In connection with the 2001 and 2000 acquisitions, the Company has
undertaken certain restructurings of the acquired businesses. The restructuring
activities include certain reductions in staffing levels, elimination of
duplicate facilities and other costs associated with exiting certain activities
of the acquired businesses. These restructuring activities were recorded as
costs of the acquisitions and were provided in accordance with Emerging Issues
Task Force Issue No. 95-3, "Recognition of

                                       7
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(4) ACQUISITIONS (CONTINUED)
Liabilities in Connection with a Purchase Business Combination." The Company
finalizes its restructuring plans for each business no later than one year from
the date of acquisition. Unresolved matters primarily include completion of
planned abandonments of facilities and employee severance costs for certain 2001
and 2000 acquisitions.

    The following is a summary of reserves related to such restructuring
activities:

<TABLE>
<CAPTION>
                                                        MARCH 31,   DECEMBER 31,
                                                          2001          2000
                                                        ---------   ------------
<S>                                                     <C>         <C>
Reserves, Beginning Balance...........................   $28,514       $ 9,340
Reserves Established..................................       314        31,409
Expenditures..........................................    (3,473)       (7,539)
Adjustments to Goodwill...............................      (631)       (4,696)
                                                         -------       -------
Reserves, Ending Balance..............................   $24,724       $28,514
                                                         =======       =======
</TABLE>

    At March 31, 2001, the restructuring reserves related to acquisitions
consisted of lease losses on abandoned facilities ($15,783), severance costs for
approximately 16 people ($1,376) and other exit costs ($7,565). These accruals
are expected to be used within one year of the finalization of the restructuring
plans except for lease losses of $10,302 and severance contracts of
approximately $674, all of which are based on contracts that extend beyond one
year.

                                       8
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(5) LONG-TERM DEBT

    Long-term debt consists of the following:

<TABLE>
<CAPTION>
                                                      MARCH 31, 2001         DECEMBER 31, 2000
                                                   ---------------------   ---------------------
                                                    CARRYING      FAIR      CARRYING      FAIR
                                                     AMOUNT      VALUE       AMOUNT      VALUE
                                                   ----------   --------   ----------   --------
<S>                                                <C>          <C>        <C>          <C>
Revolving Credit Facility due 2005...............  $   51,000   $ 51,000   $    4,000   $  4,000
Tranche A Term Loan due 2005.....................     150,000    150,000      150,000    150,000
Tranche B Term Loan due 2006.....................     199,500    199,500      199,750    199,750
11 1/8% Senior Subordinated Notes due 2006 (the
  "11 1/8% notes")...............................     131,366    138,800      131,517    136,500
10 1/8% Senior Subordinated Notes due 2006 (the
  "10 1/8% notes")...............................     165,000    173,700      165,000    170,800
9 1/8% Senior Subordinated Notes due 2007 (the
  "9 1/8% notes")................................     114,438    121,800      114,216    118,800
8 3/4% Senior Subordinated Notes due 2009 (the
  "8 3/4% notes")................................     249,656    254,400      249,646    245,600
8 1/4% Senior Subordinated Notes due 2011 (the
  "8 1/4% notes")................................     149,546    148,900      149,535    141,400
8 1/8% Senior Subordinated Notes due 2008 (the
  "Subsidiary notes")............................     121,327    131,000      120,850    128,600
Real Estate Mortgages............................      22,408     22,408       20,457     20,457
Seller Notes.....................................      12,817     12,817       13,971     13,971
Other............................................      36,013     36,013       36,189     36,189
                                                   ----------              ----------
Long-term debt...................................   1,403,071               1,355,131
Less current portion.............................     (31,629)                (40,789)
                                                   ----------              ----------
Long-term debt, net of current portion...........  $1,371,442              $1,314,342
                                                   ==========              ==========
</TABLE>

    The estimated fair values for the long-term debt are based on the borrowing
rates available to the Company at March 31, 2001 and December 31, 2000 for loans
with similar terms and average maturities. The fair values of the 11 1/8% notes,
10 1/8% notes, 9 1/8% notes, 8 3/4% notes, 8 1/4% notes (collectively, the
"Parent Notes") and the Subsidiary notes are based on the quoted market prices
for those notes on March 31, 2001 and December 31, 2000.

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS

    The following financial data summarizes the consolidating Company on the
equity method of accounting as of March 31, 2001 and December 31, 2000 and for
the first quarter of 2001 and 2000. The Guarantor column includes all
subsidiaries that guarantee the Parent notes and the Subsidiary notes. The
Canada Company column includes Iron Mountain Canada Corporation ("Canada
Company"), the issuer of the Subsidiary notes, and the Company's other Canadian
subsidiaries that guarantee the Subsidiary notes, but do not guarantee the
Parent notes. The Parent and the Guarantors

                                       9
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)
also guarantee the Subsidiary notes. The subsidiaries that do not guarantee
either the Parent notes or the Subsidiary notes are referred to in the table as
the "non-guarantors."

<TABLE>
<CAPTION>
                                                                MARCH 31, 2001
                                 -----------------------------------------------------------------------------
                                                            CANADA       NON-
                                   PARENT     GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                 ----------   ----------   --------   ----------   ------------   ------------
<S>                              <C>          <C>          <C>        <C>          <C>            <C>
ASSETS
Current Assets:
  Cash and Cash Equivalents....  $       --   $    2,863   $  1,321    $  5,719    $        --     $    9,903
  Accounts Receivable..........          --      172,679     14,184      21,194             --        208,057
  Intercompany Receivable
    (Payable)..................     824,947     (712,933)   (86,024)    (25,990)            --             --
  Other Current Assets.........          --       52,707        734       5,377             --         58,818
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Current Assets.....     824,947     (484,684)   (69,785)      6,300             --        276,778
Property, Plant and Equipment,
  net..........................          --      707,771     68,413      85,119             --        861,303
Other Assets:
  Long-term Intercompany
    Receivable.................     331,006           --         --          --       (331,006)            --
  Long-term Notes Receivable
    from Affiliates............     623,900           --         --          --       (623,900)            --
  Investment in Subsidiaries...     375,879       75,590         --          --       (451,469)            --
  Goodwill, net................          --    1,268,922    120,304     136,513         10,162      1,535,901
  Other........................      15,946       43,536      9,704         579         (5,693)        64,072
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Other Assets.......   1,346,731    1,388,048    130,008     137,092     (1,401,906)     1,599,973
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Assets.............  $2,171,678   $1,611,135   $128,636    $228,511    $(1,401,906)    $2,738,054
                                 ==========   ==========   ========    ========    ===========     ==========

LIABILITIES AND SHAREHOLDERS'
  EQUITY
  Total Current Liabilities....  $   28,174   $  200,716   $ 15,679    $ 65,237    $        --     $  309,806
  Long-term Debt, Net of
    Current Portion............   1,217,569        3,791    126,119      23,963             --      1,371,442
  Long-term Intercompany
    Payable....................          --      331,006         --          --       (331,006)            --
  Long-term Notes Payable to
    Affiliates.................          --      623,900         --          --       (623,900)            --
  Other Long-term
    Liabilities................          --       64,858        108       2,326         (5,693)        61,599
  Minority Interest............          --           --         --         727         68,545         69,272
  Shareholders' Equity.........     925,935      386,864    (13,270)    136,258       (509,852)       925,935
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Liabilities and
        Shareholders' Equity...  $2,171,678   $1,611,135   $128,636    $228,511    $(1,401,906)    $2,738,054
                                 ==========   ==========   ========    ========    ===========     ==========
</TABLE>

                                       10
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)

<TABLE>
<CAPTION>
                                                               DECEMBER 31, 2000
                                 -----------------------------------------------------------------------------
                                                            CANADA       NON-
                                   PARENT     GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                 ----------   ----------   --------   ----------   ------------   ------------
<S>                              <C>          <C>          <C>        <C>          <C>            <C>
ASSETS
Current Assets:
  Cash and Cash Equivalents....  $      191   $    3,336   $    302    $  2,371    $        --     $    6,200
  Accounts Receivable..........       7,060      140,095     12,370      16,917             --        176,442
  Intercompany Receivable
    (Payable)..................     795,522     (658,022)   (98,386)    (45,060)         5,946             --
  Other Current Assets.........         531       46,605        827       6,063             --         54,026
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Current Assets.....     803,304     (467,986)   (84,887)    (19,709)         5,946        236,668
Property, Plant and Equipment,
  net..........................      99,549      586,504     66,953      79,388             --        832,394
Other Assets:
  Long-term Intercompany
    Receivable.................     344,300           --         --          --       (344,300)            --
  Long-term Notes Receivable
    from Affiliates............     607,600      124,100         --          --       (731,700)            --
  Investment in Subsidiaries...     370,830       49,626         --          --       (420,456)            --
  Goodwill, net................          --    1,255,302    138,663     121,096         10,569      1,525,630
  Other........................      20,986       42,956     11,036       1,834        (12,408)        64,404
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Other Assets.......   1,343,716    1,471,984    149,699     122,930     (1,498,295)     1,590,034
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Assets.............  $2,246,569   $1,590,502   $131,765    $182,609    $(1,492,349)    $2,659,096
                                 ==========   ==========   ========    ========    ===========     ==========

LIABILITIES AND SHAREHOLDERS'
  EQUITY
  Total Current Liabilities....  $   26,921   $  189,362   $ 12,429    $ 79,378    $     5,963     $  314,053
  Long-term Debt, Net of
    Current Portion............   1,170,884        3,513    124,834      15,111             --      1,314,342
  Long-term Intercompany
    Payable....................          --      344,300         --          --       (344,300)            --
  Long-term Notes Payable to
    Affiliates.................     124,100      607,600         --          --       (731,700)            --
  Other Long-term
    Liabilities................         206       73,693        113       1,610        (12,408)        63,214
  Minority Interest............          --           --         --      (1,636)        44,665         43,029
  Shareholders' Equity.........     924,458      372,034     (5,611)     88,146       (454,569)       924,458
                                 ----------   ----------   --------    --------    -----------     ----------
      Total Liabilities and
        Shareholders' Equity...  $2,246,569   $1,590,502   $131,765    $182,609    $(1,492,349)    $2,659,096
                                 ==========   ==========   ========    ========    ===========     ==========
</TABLE>

                                       11
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)

<TABLE>
<CAPTION>
                                                        THREE MONTHS ENDED MARCH 31, 2001
                                   ---------------------------------------------------------------------------
                                                            CANADA       NON-
                                    PARENT    GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                   --------   ----------   --------   ----------   ------------   ------------
<S>                                <C>        <C>          <C>        <C>          <C>            <C>
Revenues:
  Storage........................  $     --    $146,575    $ 8,402     $12,888       $     --       $167,865
  Service and Storage Material
    Sales........................        --      99,988      8,267       7,802             --        116,057
                                   --------    --------    -------     -------       --------       --------
      Total Revenues.............        --     246,563     16,669      20,690             --        283,922

Operating Expenses:
  Cost of Sales (Excluding
    Depreciation)................        --     119,490      8,737      11,593             --        139,820
  Selling, General and
    Administrative...............        75      62,273      2,751       5,218             --         70,317
  Depreciation and
    Amortization.................        --      30,488      2,484       2,746             --         35,718
  Merger-Related Expenses........        --         772         --          29             --            801
                                   --------    --------    -------     -------       --------       --------
      Total Operating Expenses...        75     213,023     13,972      19,586             --        246,656
                                   --------    --------    -------     -------       --------       --------

Operating Income (Loss)..........       (75)     33,540      2,697       1,104             --         37,266

Interest Expense, net............    13,170      14,881      4,050       1,886             --         33,987
Equity in the (Earnings) Losses
  of Subsidiaries................   (16,444)         85         --          --         16,359             --
Other Expense, net...............        --      (2,892)    (6,294)         (1)            --         (9,187)
                                   --------    --------    -------     -------       --------       --------

      Income (Loss) Before
        Provision (Benefit) for
        Income Taxes and Minority
        Interest Expense.........     3,199      15,682     (7,647)       (783)       (16,359)        (5,908)

Provision (Benefit) for Income
  Taxes..........................        --      (9,100)       617        (354)            --         (8,837)
Minority Interests in Losses of
  Subsidiaries...................        --          --         --        (270)            --           (270)
                                   --------    --------    -------     -------       --------       --------

      Net Income (Loss)..........  $  3,199    $ 24,782    $(8,264)    $  (159)      $(16,359)      $  3,199
                                   ========    ========    =======     =======       ========       ========
</TABLE>

                                       12
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)

<TABLE>
<CAPTION>
                                                         THREE MONTHS ENDED MARCH 31, 2000
                                    ---------------------------------------------------------------------------
                                                             CANADA       NON-
                                     PARENT    GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                    --------   ----------   --------   ----------   ------------   ------------
<S>                                 <C>        <C>          <C>        <C>          <C>            <C>
Revenues:
  Storage.........................  $   574     $111,076    $ 4,360     $ 8,929        $    --       $124,939
  Service and Storage Material
    Sales.........................    3,249       72,504      5,356       6,592           (503)        87,198
                                    -------     --------    -------     -------        -------       --------
      Total Revenues..............    3,823      183,580      9,716      15,521           (503)       212,137

Operating Expenses:
  Cost of Sales (Excluding
    Depreciation).................    2,236       89,884      5,136       9,070         (1,868)       104,458
  Selling, General and
    Administrative................      660       45,922      1,931       3,579          1,365         53,457
  Depreciation and Amortization...      341       22,801      1,062       2,099             --         26,303
  Merger-Related Expenses.........       --          516         --          --             --            516
                                    -------     --------    -------     -------        -------       --------
      Total Operating Expenses....    3,237      159,123      8,129      14,748           (503)       184,734
                                    -------     --------    -------     -------        -------       --------

Operating Income..................      586       24,457      1,587         773             --         27,403

Interest Expense, net.............    6,818       13,510      2,304       1,151             --         23,783
Equity in the (Earnings) Losses of
  Subsidiaries....................      352         (102)        --          --           (250)            --
Other Income (Expense), net.......       --           66       (846)         (1)            --           (781)
                                    -------     --------    -------     -------        -------       --------

      Income (Loss) Before
        Provision (Benefit) for
        Income Taxes and Minority
        Interest Expense..........   (6,584)      11,115     (1,563)       (379)           250          2,839

Provision (Benefit) for Income
  Taxes...........................   (1,201)       9,970       (199)        (41)            --          8,529
Minority Interests in Losses of
  Subsidiaries....................       --           --         --        (307)            --           (307)
                                    -------     --------    -------     -------        -------       --------

      Net Income (Loss)...........  $(5,383)    $  1,145    $(1,364)    $   (31)       $   250       $ (5,383)
                                    =======     ========    =======     =======        =======       ========
</TABLE>

                                       13
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)

<TABLE>
<CAPTION>
                                                        THREE MONTHS ENDED MARCH 31, 2001
                                   ---------------------------------------------------------------------------
                                                            CANADA       NON-
                                    PARENT    GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                   --------   ----------   --------   ----------   ------------   ------------
<S>                                <C>        <C>          <C>        <C>          <C>            <C>
Cash Flows from Operating
  Activities:
  Cash Flows Provided by (Used
    in) Operating Activities.....  $(21,070)   $ 45,009    $ 1,642     $ (1,682)     $     --       $ 23,899
Cash Flows from Investing
  Activities:
  Capital Expenditures...........        --     (42,528)    (1,592)      (4,078)           --        (48,198)
  Cash Paid for Acquisitions, net
    of cash acquired.............        --     (19,813)       206      (15,166)           --        (34,773)
  Intercompany Loans to
    Subsidiaries.................   (20,204)      2,537         --           --        17,667             --
  Investment in Subsidiaries.....    (6,523)     (6,523)        --           --        13,046             --
  Additions to Customer
    Acquisition Costs............        --      (2,051)       (75)        (181)           --         (2,307)
  Proceeds from Sales of Property
    and Equipment................        --           8          5           16            --             29
                                   --------    --------    -------     --------      --------       --------
      Cash Flows Used in
        Investing Activities.....   (26,727)    (68,370)    (1,456)     (19,409)       30,713        (85,249)
Cash Flows from Financing
  Activities:
  Repayment of Debt..............      (883)    (34,043)       (60)        (748)           --        (35,734)
  Proceeds from Borrowings.......    46,116      35,686         --          553            --         82,355
  Debt Repayment to Minority
    Shareholders.................        --          --         --       (6,560)           --         (6,560)
  Equity Contributions from
    Minority Shareholders........        --          --         --       24,529            --         24,529
  Intercompany Loans from
    Parent.......................        --      14,791      4,937       (2,061)      (17,667)            --
  Equity Contribution from
    Parent.......................        --       6,523         --        6,523       (13,046)            --
  Proceeds from Exercise of Stock
    Options......................     2,539          --         --           --            --          2,539
  Debt Financing and Stock
    Issuance Costs...............      (166)        (69)        --           --            --           (235)
                                   --------    --------    -------     --------      --------       --------
      Cash Flows Provided by
        Financing Activities.....    47,606      22,888      4,877       22,236       (30,713)        66,894
Effect of Exchange Rates on Cash
  and Cash Equivalents...........        --          --     (4,044)       2,203            --         (1,841)
Increase (Decrease) in Cash and
  Cash Equivalents...............      (191)       (473)     1,019        3,348            --          3,703
Cash and Cash Equivalents,
  Beginning of Period............       191       3,336        302        2,371            --          6,200
                                   --------    --------    -------     --------      --------       --------
Cash and Cash Equivalents, End of
  Period.........................  $     --    $  2,863    $ 1,321     $  5,719      $     --       $  9,903
                                   ========    ========    =======     ========      ========       ========
</TABLE>

                                       14
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(6) SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND
    NON-GUARANTORS (CONTINUED)

<TABLE>
<CAPTION>
                                                       THREE MONTHS ENDED MARCH 31, 2000
                                  ----------------------------------------------------------------------------
                                                            CANADA       NON-
                                   PARENT     GUARANTORS   COMPANY    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                  ---------   ----------   --------   ----------   ------------   ------------
<S>                               <C>         <C>          <C>        <C>          <C>            <C>
Cash Flows from Operating
  Activities:
  Cash Flows Provided by (Used
    in) Operating Activities....  $  (7,077)  $  27,535    $(1,347)    $(1,393)      $      --     $  17,718
Cash Flows from Investing
  Activities:
  Capital Expenditures..........     (2,471)    (19,909)    (1,999)     (3,267)             --       (27,646)
  Cash Paid for Acquisitions,
    net of Cash Acquired........     (3,895)       (565)        55      (1,231)             --        (5,636)
  Intercompany Loans to
    Subsidiaries................   (185,715)    (10,527)        --          --         196,242            --
  Investment in Subsidiaries....         --      (1,591)        --          --           1,591            --
  Additions to Customer
    Acquisition Costs...........         --      (2,696)      (183)       (477)             --        (3,356)
  Other, Net....................         --          91        (45)       (481)             --          (435)
                                  ---------   ---------    -------     -------       ---------     ---------
      Cash Flows Used in
        Investing Activities....   (192,081)    (35,197)    (2,172)     (5,456)        197,833       (37,073)
Cash Flows from Financing
  Activities:
  Repayment of Debt.............    (28,550)   (172,192)      (176)     (2,349)             --      (203,267)
  Proceeds from Borrowings......    220,500       1,885      1,173          --              --       223,558
  Debt Financing and Equity
    Contribution from Minority
    Shareholders................         --          --         --       7,036              --         7,036
  Intercompany Loans from
    Parent......................      9,519     179,320      1,165       6,238        (196,242)           --
  Equity Contribution from
    Parent......................         --          --      1,591          --          (1,591)           --
  Proceeds from Exercise of
    Stock Options...............        885          --         --          --              --           885
  Debt Financing and Stock
    Issuance Costs..............     (2,769)         --         --          --              --        (2,769)
                                  ---------   ---------    -------     -------       ---------     ---------
      Cash Flows Provided by
        Financing Activities....    199,585       9,013      3,753      10,925        (197,833)       25,443
Effect of Exchange Rates on Cash
  and Cash Equivalents..........         --          --        (50)        236              --           186
Increase in Cash and Cash
  Equivalents...................        427       1,351        184       4,312              --         6,274
Cash and Cash Equivalents,
  Beginning of Period...........         --       2,260         --       1,570              --         3,830
                                  ---------   ---------    -------     -------       ---------     ---------
Cash and Cash Equivalents, End
  of Period.....................  $     427   $   3,611    $   184     $ 5,882       $      --     $  10,104
                                  =========   =========    =======     =======       =========     =========
</TABLE>

                                       15
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(7) EARNINGS PER SHARE

   In accordance with SFAS No. 128, "Earnings per Share," basic net income
(loss) per common share is calculated by dividing net income (loss) by the
weighted average number of common shares outstanding. The calculation of diluted
net income (loss) per share is consistent with that of basic net income (loss)
per share but gives effect to all potential common shares (that is, securities
such as options, warrants or convertible securities) that were outstanding
during the period, unless the effect is antidilutive.

(8) SEGMENT INFORMATION

    An analysis of the Company's business segment information to the respective
information in the consolidated financial statements is as follows:

<TABLE>
<CAPTION>
                                       BUSINESS     OFF SITE
                                       RECORDS        DATA                      CORPORATE       TOTAL
                                      MANAGEMENT   PROTECTION   INTERNATIONAL    & OTHER     CONSOLIDATED
                                      ----------   ----------   -------------   ----------   ------------
<S>                                   <C>          <C>          <C>             <C>          <C>
THREE MONTHS ENDED MARCH 31, 2001
Revenue.............................   $189,922      $44,916       $36,879      $   12,205    $  283,922
EBITDA..............................     50,214       10,438         8,679           4,454        73,785
Total Assets........................    914,515       73,114       345,960       1,404,465     2,738,054

THREE MONTHS ENDED MARCH 31, 2000
Revenue.............................    144,210       38,615        24,874           4,438       212,137
EBITDA..............................     38,482        8,559         4,958           2,223        54,222
</TABLE>

    A reconciliation from the segment information to the consolidated balances
for income (loss) before provision (benefit) for income taxes and minority
interest is as follows:

<TABLE>
<CAPTION>
                                                  THREE MONTHS ENDED MARCH 31,
                                                  -----------------------------
                                                      2001            2000
                                                  -------------   -------------
<S>                                               <C>             <C>
EBITDA..........................................    $ 73,785        $ 54,222
Depreciation and Amortization...................     (35,718)        (26,303)
Merger-related Expenses.........................        (801)           (516)
Interest Expense................................     (33,987)        (23,783)
Other Expense, net..............................      (9,187)           (781)
                                                    --------        --------
    Income (Loss) Before Provision (Benefit) for
      Income Taxes and Minority Interest........    $ (5,908)       $  2,839
                                                    ========        ========
</TABLE>

                                       16
<PAGE>
                           IRON MOUNTAIN INCORPORATED

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

                                 (IN THOUSANDS)

                                  (UNAUDITED)

                                  (CONTINUED)

(8) SEGMENT INFORMATION (CONTINUED)
    Information as to the Company's operations in different geographical areas
is as follows:

<TABLE>
<CAPTION>
                                                  THREE MONTHS ENDED MARCH 31,
                                                  -----------------------------
                                                      2001            2000
                                                  -------------   -------------
<S>                                               <C>             <C>
Revenues:
United States...................................   $  247,043      $  187,263
International...................................       36,879          24,874
                                                   ----------      ----------
  Total Revenues................................   $  283,922      $  212,137
                                                   ==========      ==========
</TABLE>

<TABLE>
<CAPTION>
                                                  MARCH 31, 2001   MARCH 31, 2000
                                                  --------------   --------------
<S>                                               <C>              <C>
Long-lived Assets:
United States...................................    $2,054,517       $1,924,769
International...................................       406,759          330,018
                                                    ----------       ----------
  Total Long-lived Assets.......................    $2,461,276       $2,254,787
                                                    ==========       ==========
</TABLE>

(9) SUBSEQUENT EVENTS

    In April 2001, Iron Mountain completed an underwritten public offering of
$225,000 in aggregate principal amount of 8 5/8% Senior Subordinated Notes due
2013. The 8 5/8% notes were issued at a price to investors of 100% of par. The
net proceeds to the Company, approximately $219,000 after paying the
underwriters' discounts and commissions and estimated expenses, were used to
fund the Company's offer to purchase and consent solicitation relating to its
outstanding 11 1/8% Senior Subordinated Notes due 2006, to repay outstanding
borrowings under the Company's revolving credit facility and for general
corporate purposes, including acquisitions.

    In April 2001, the Company received and accepted tenders for $124,588 of the
outstanding principal amount of its 11 1/8% notes. The Company expects to record
an extraordinary charge of approximately $5,000 (net of tax benefit) in the
second quarter related to the early retirement of the 11 1/8% notes. The Company
intends to redeem the remaining $5,412 of outstanding principal amount of the
11 1/8% notes in July 2001, the first redemption date, at a redemption price
(expressed as a percentage of principal amount) of 105.563%, plus accrued and
unpaid interest to, but not including, the date of redemption.

                                       17
<PAGE>
                           IRON MOUNTAIN INCORPORATED

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
  OF OPERATIONS

    The following discussion and analysis of the Company's financial condition
and results of operations for the three months ended March 31, 2001 and 2000
should be read in conjunction with the condensed consolidated financial
statements and footnotes for the three months ended March 31, 2001 included
herein, and the year ended December 31, 2000, included in the Company's Annual
Report on Form 10-K filed with the Securities and Exchange Commission on
March 23, 2001.

OVERVIEW

    The Company's consolidated revenues increased $71.8 million, or 33.8%, to
$283.9 million for the first quarter of 2001 from $212.1 million for the first
quarter of 2000. Internal revenue growth, calculated in local currency for our
international operations and as if Pierce Leahy Corp. had merged with Iron
Mountain on January 1, 2000, was 11.2%.

    During the first quarter of 2001, the Company acquired six records and
information management services businesses for total consideration of
$41.0 million. These six acquisitions reported approximately $15 million in
revenues for the fiscal year 2000.

RESULTS OF OPERATIONS

THREE MONTHS ENDED MARCH 31, 2001 COMPARED TO THREE MONTHS ENDED MARCH 31, 2000

    Consolidated storage revenues increased $42.9 million, or 34.4%, to
$167.9 million for the first three months of 2001, from $124.9 million for the
first three months of 2000. The increase was attributable to: (i) acquisitions,
particularly the Pierce Leahy acquisition; and (ii) internal revenue growth of
12.7% resulting primarily from net increases in records and other media stored
by existing customers, price increases and sales to new customers. The total
increase in storage revenues was partially offset by the unfavorable effects of
currency translation as a result of the strengthening of the U.S. dollar against
certain foreign currencies, primarily the Canadian dollar and the British pound
sterling, in which the Company's international segment does business.

    Consolidated service and storage material sales revenues increased
$28.9 million, or 33.1%, to $116.1 million for the first three months of 2001,
from $87.2 million for the first three months of 2000. The increase was
attributable to: (i) acquisitions, particularly the Pierce Leahy acquisition;
and (ii) internal revenue growth of 9.0% resulting primarily from net increases
in service and storage material sales to existing customers, price increases and
sales to new customers. The total increase in service and storage material sales
revenues was partially offset by the unfavorable effects of currency translation
as a result of the strengthening of the U.S. dollar against certain foreign
currencies, primarily the Canadian dollar and the British pound sterling, in
which the Company's international segment does business.

    For the reasons discussed above, total consolidated revenues increased
$71.8 million, or 33.8%, to $283.9 million for the first three months of 2001
from $212.1 million for the first three months of 2000.

    Consolidated cost of sales (excluding depreciation) increased
$35.4 million, or 33.9%, to $139.8 million (49.2% of consolidated revenues) for
the first three months of 2001 from $104.5 million (49.2% of consolidated
revenues) for the first three months of 2000. The dollar increase was consistent
with the revenue growth of the Company.

    Consolidated selling, general and administrative expenses increased
$16.9 million, or 31.5%, to $70.3 million (24.8% of consolidated revenues) for
the first three months of 2001 from $53.5 million (25.2% of consolidated
revenues) for the first three months of 2000. The dollar increase was primarily

                                       18
<PAGE>
                           IRON MOUNTAIN INCORPORATED

attributable to revenue growth of the Company. The percentage decrease was
primarily attributable to general management overhead efficiencies due to an
increase in scale partially offset by: (i) increased spending in Europe and
Latin America as a percentage of revenues and (ii) spending in the first quarter
of 2001 for the Company's marketing and information technology initiatives
related to the development of complementary technology-based service offerings.

    As a result of the foregoing factors, consolidated EBITDA increased
$19.6 million, or 36.1%, to $73.8 million (26.0% of consolidated revenues) for
the first three months of 2001 from $54.2 million (25.6% of consolidated
revenues) for the first three months of 2000. Excluding the $0.9 million of
expenses related to the Company's technology-related service offerings, the
Company's EBITDA margin for the first three months of 2001 was 26.3% of
consolidated revenues. There were no such costs in the first three months of
2000.

    Consolidated depreciation and amortization expense increased $9.4 million,
or 35.8%, to $35.7 million (12.6% of consolidated revenues) for the first three
months of 2001 from $26.3 million (12.4% of consolidated revenues) for the first
three months of 2000. The dollar increase was primarily attributable to the
additional depreciation and amortization expense related to the 2000 and 2001
acquisitions, particularly the Pierce Leahy acquisition, and capital
expenditures including racking systems, information systems and expansion of
storage capacity in existing facilities.

    Merger-related expenses are certain expenses directly related to the
Company's merger with Pierce Leahy that cannot be capitalized and include system
conversion costs, costs of exiting certain facilities, severance, relocation and
pay-to-stay payments and other transaction-related costs. Merger-related
expenses were $0.8 million for the first three months of 2001 compared to
$0.5 million for the first three months of 2000.

    As a result of the foregoing factors, consolidated operating income
increased $9.9 million, or 36.0%, to $37.3 million (13.1% of consolidated
revenues) for the first three months of 2001 from $27.4 million (12.9% of
consolidated revenues) for the first three months of 2000.

    Consolidated interest expense increased $10.2 million, or 42.9%, to
$34.0 million for the first three months of 2001 from $23.8 million for the
first three months of 2000. The increase was primarily attributable to increased
indebtedness related to: (i) the inclusion of Pierce Leahy's debt for three
months of 2001 versus two months of 2000 and (ii) the financing of acquisitions
and capital expenditures.

    Consolidated other expense was $9.2 million for the first three months of
2001 compared to $0.8 million for the first three months of 2000. The increase
was primarily due to a weakening of the Canadian dollar against the U.S. dollar,
as it relates to Canada Company's 8 1/8% Senior Subordinated Notes due 2008 and
on intercompany balances with the Company's Canadian subsidiaries and a
weakening of the British pound sterling against the U.S. dollar on intercompany
balances with the Company's European subsidiaries.

    As a result of the foregoing factors, consolidated income (loss) before
provision (benefit) for income taxes and minority interest decreased
$8.7 million to a loss of $5.9 million (2.1% of consolidated revenues) for the
first three months of 2001 from income of $2.8 million (1.3% of consolidated
revenues) for the first three months of 2000. The benefit for income taxes was
$8.8 million for the first three months of 2001 compared to a provision of
$8.5 million for the first three months of 2000. The benefit was calculated by
applying the Company's effective tax rate to the pre-tax loss. The Company's
effective tax rate is based on an estimate of annual pre-tax income and is
higher than statutory rates primarily due to the amortization of the
nondeductible portion of goodwill associated

                                       19
<PAGE>
                           IRON MOUNTAIN INCORPORATED

with particular acquisitions. For the three months ended March 31, 2001, the
Company recorded $9.6 million in nondeductible goodwill amortization expense.

    Consolidated net income increased $8.6 million to $3.2 million (1.1% of
consolidated revenues) for the first three months of 2001 from a net loss of
$5.4 million (2.5% of consolidated revenues) for the first three months of 2000.

LIQUIDITY AND CAPITAL RESOURCES

    As the Company has sought to increase its EBITDA, it has made significant
capital investments, consisting primarily of: (i) capital expenditures,
primarily related to growth (including investments in real estate, racking
systems, information systems and expansion of storage capacity in existing
facilities); (ii) acquisitions; and (iii) customer acquisition costs. Cash paid
for these investments during the first three months of 2001 amounted to
$48.2 million, $34.8 million and $2.3 million, respectively. These investments
have been primarily funded through cash flows from operations and borrowings
under the Company's credit agreements. Included in capital expenditures is
$1.5 million related to the Company's technology-based service offerings.

    Net cash provided by operations was $23.9 million for the first three months
of 2001 compared to $17.7 million for the same period in 2000. The increase
primarily resulted from an increase in EBITDA and an increase in accrued
expenses, which was partially offset by an increase in trade accounts receivable
and a decrease in the net deferred tax liability.

    Net cash provided by financing activities was $66.9 million for the first
three months of 2001, consisting primarily of the proceeds from borrowings under
the Company's revolving credit facility of $81.8 million and equity
contributions from minority shareholders of $24.5 million, which were partially
offset by repayments of debt of $35.7 million.

    In April 2001, Iron Mountain completed an underwritten public offering of
$225.0 million in aggregate principal amount of 8 5/8% Senior Subordinated Notes
due 2013. The 8 5/8% notes were issued at a price to investors of 100% of par.
The net proceeds to the Company, approximately $219 million after paying the
underwriters' discounts and commissions and estimated expenses, were used to
fund the Company's offer to purchase and consent solicitation relating to its
outstanding 11 1/8% Senior Subordinated Notes due 2006, to repay outstanding
borrowings under the Company's revolving credit facility and for general
corporate purposes, including acquisitions.

    In April 2001, the Company received and accepted tenders for $124.6 million
of the outstanding principal amount of its 11 1/8% notes. The Company expects to
record an extraordinary charge of approximately $5 million (net of tax benefit)
in the second quarter related to the early retirement of the 11 1/8% notes. The
Company intends to redeem the remaining $5.4 million of outstanding principal
amount of the 11 1/8% notes in July 2001, the first redemption date, at a
redemption price (expressed as a percentage of principal amount) of 105.563%,
plus accrued and unpaid interest to, but not including, the date of redemption.

                                       20
<PAGE>
                           IRON MOUNTAIN INCORPORATED

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

    In December 2000 and January 2001, the Company entered into certain
derivative financial contracts, which were variable-for-fixed swaps of interest
payments payable on the Company's Tranche B term loan and certain variable
operating lease commitments.

    Iron Mountain's investments in Iron Mountain Europe Limited, Iron Mountain
South America, Ltd. and other international investments may be subject to risks
and uncertainties relating to fluctuations in currency valuation. One of the
Company's Canadian subsidiaries, Canada Company, has U.S. dollar denominated
debt. Gains and losses due to exchange rate fluctuations related to this debt
are recognized in the Company's consolidated statements of operations.

    As of March 31, 2001, the Company had $230.3 million of variable rate debt
outstanding with a weighted average interest rate of 7.72% and $1,172.8 million
of fixed rate debt outstanding. If the weighted average variable interest rate
had increased by 1%, such increase would have had a negative impact on the
Company's net income for the quarter ended March 31, 2001 of $0.3 million. See
Note 4 of Notes to Consolidated Financial Statements for a discussion of the
Company's long-term indebtedness, including the fair values of such indebtedness
as of March 31, 2001.

PART II. OTHER INFORMATION

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

(a) EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT NO.                           DESCRIPTION
-----------                           -----------
<C>           <S>
    4.1       Subordinated Indenture, dated as of April 3, 2001, among the
              Company, the Guarantors named therein and The Bank of New
              York, as trustee.

    4.2       First Supplemental Indenture, dated as of April 3, 2001,
              among the Company, the Guarantors named therein and The Bank
              of New York, as trustee
</TABLE>

(b) REPORTS ON FORM 8-K

    On March 23, 2001, the Company filed a Current Report on Form 8-K under
Items 5 and 7 to announce the Company's proposed underwritten public offering of
Senior Subordinated Notes and related tender offer and consent solicitation. The
Current Report on Form 8-K also provided unaudited pro forma financial
information with respect to acquisitions by the Company of businesses in 2000
and certain other financing transactions described therein.

    On April 3, 2001, the Company filed a Current Report on Form 8-K under Items
5 and 7 to file certain documents in connection with a prospectus supplement,
dated March 27, 2001, filed by the Company on March 28, 2001.

                                       21
<PAGE>
                           IRON MOUNTAIN INCORPORATED

    Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

<TABLE>
<S>                                                    <C>  <C>
                                                       IRON MOUNTAIN INCORPORATED

                    May 15, 2001                       By:               /s/ JEAN A. BUA
                       (date)                               -----------------------------------------
                                                                           Jean A. Bua
                                                             VICE PRESIDENT AND CORPORATE CONTROLLER
                                                                  (PRINCIPAL ACCOUNTING OFFICER)
</TABLE>

                                       22
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.1
<SEQUENCE>2
<FILENAME>a2049379zex-4_1.txt
<DESCRIPTION>EXHIBIT 4.1
<TEXT>

<PAGE>

                                                                  EXECUTION COPY

--------------------------------------------------------------------------------

                           IRON MOUNTAIN INCORPORATED

                                ----------------

                             SUBORDINATED INDENTURE

                            Dated as of April 3, 2001

                                ----------------

                              THE BANK OF NEW YORK,

                                   as Trustee

--------------------------------------------------------------------------------

<PAGE>

                                                                  EXECUTION COPY

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                            Page
                                                                            ----

<S>                                                                        <C>
ARTICLE I. DEFINITIONS AND INCORPORATION BY REFERENCE.........................1
     Section 1.1.      Definitions............................................1
     Section 1.2.      Other Definitions......................................7
     Section 1.3.      Incorporation by Reference of Trust Indenture Act......8
     Section 1.4.      Rules of Construction..................................8
ARTICLE II. THE SECURITIES....................................................9
     Section 2.1.      Issuable in Series.....................................9
     Section 2.2.      Establishment of Terms of Series of Securities.........9
     Section 2.3.      Execution and Authentication...........................11
     Section 2.4.      Registrar and Paying Agent.............................12
     Section 2.5.      Paying Agent to Hold Money in Trust....................13
     Section 2.6.      Securityholder Lists...................................13
     Section 2.7.      Transfer and Exchange..................................14
     Section 2.8.      Mutilated, Destroyed, Lost and Stolen Securities.......14
     Section 2.9.      Outstanding Securities.................................15
     Section 2.10.     Treasury Securities....................................15
     Section 2.11.     Temporary Securities...................................16
     Section 2.12.     Cancellation...........................................16
     Section 2.13.     Defaulted Interest.....................................16
     Section 2.14.     Record Date............................................17
     Section 2.15.     Global Securities......................................17
     Section 2.16.     CUSIP Numbers..........................................18
ARTICLE III. REDEMPTION.......................................................18
     Section 3.1.      Notice to Trustee......................................18
     Section 3.2.      Selection of Securities to be Redeemed.................19
     Section 3.3.      Notice of Redemption...................................19
     Section 3.4.      Effect of Notice of Redemption.........................20
     Section 3.5.      Deposit of Redemption Price............................20
     Section 3.6.      Securities Redeemed in Part............................20
ARTICLE IV. COVENANTS.........................................................21
     Section 4.1.      Payment of Principal and Interest......................21
     Section 4.2.      SEC Reports............................................21
     Section 4.3.      Compliance Certificate.................................21
     Section 4.4.      Stay, Extension and Usury Laws.........................21
     Section 4.5.      Corporate Existence....................................22
     Section 4.6.      Taxes..................................................22
     Section 4.7       Maintenance of Office or Agency........................22
ARTICLE V. SUCCESSORS.........................................................23
     Section 5.1.      When Company May Merge, Etc............................23
     Section 5.2.      Successor Corporation Substituted......................23
ARTICLE VI. DEFAULTS AND REMEDIES.............................................23
     Section 6.1.      Events of Default......................................23


                                       i
<PAGE>

     Section 6.2.      Acceleration of Maturity; Rescission and Annulment.....25
     Section 6.3.      Collection of Indebtedness and Suits for Enforcement
                       by Trustee.............................................26
     Section 6.4.      Trustee May File Proofs of Claim.......................27
     Section 6.5.      Trustee May Enforce Claims Without Possession of
                       Securities.............................................28
     Section 6.6.      Application of Money Collected.........................28
     Section 6.7.      Limitation on Suits....................................28
     Section 6.8.      Unconditional Right of Holders to Receive Principal
                       and Interest...........................................29
     Section 6.9.      Restoration of Rights and Remedies.....................29
     Section 6.10.     Rights and Remedies Cumulative.........................29
     Section 6.11.     Delay or Omission Not Waiver...........................29
     Section 6.12.     Control by Holders.....................................30
     Section 6.13.     Waiver of Past Defaults................................30
     Section 6.14.     Undertaking for Costs..................................30
ARTICLE VII. TRUSTEE..........................................................31
     Section 7.1.      Duties of Trustee......................................31
     Section 7.2.      Rights of Trustee......................................32
     Section 7.3.      Individual Rights of Trustee...........................33
     Section 7.4.      Trustee's Disclaimer...................................33
     Section 7.5.      Notice of Defaults.....................................33
     Section 7.6.      Reports by Trustee to Holders..........................34
     Section 7.7.      Compensation and Indemnity.............................34
     Section 7.8.      Replacement of Trustee.................................35
     Section 7.9.      Successor Trustee by Merger, etc.......................36
     Section 7.10.     Eligibility; Disqualification..........................36
     Section 7.11.     Preferential Collection of Claims Against Company......36
ARTICLE VIII. LEGAL DEFEASANCE AND COVENANT DEFEASANCE........................36
     Section 8.1.      Option to Effect Legal Defeasance or Covenant
                       Defeasance.............................................36
     Section 8.2.      Legal Defeasance and Discharge.........................36
     Section 8.3.      Covenant Defeasance....................................37
     Section 8.4.      Conditions to Legal or Covenant Defeasance.............37
     Section 8.5.      Deposited Money and Government Securities to be
                       Held in Trust; Other Miscellaneous Provisions..........39
     Section 8.6.      Repayment to Company...................................39
     Section 8.7.      Reinstatement..........................................40
ARTICLE IX. AMENDMENTS AND WAIVERS............................................40
     Section 9.1.      Without Consent of Holders.............................40
     Section 9.2.      With Consent of Holders................................41
     Section 9.3.      Limitations............................................41
     Section 9.4.      Compliance with Trust Indenture Act....................42
     Section 9.5.      Revocation and Effect of Consents......................42
     Section 9.6.      Notation on or Exchange of Securities..................42
     Section 9.7.      Trustee to Sign Amendments; Trustee Protected..........43
ARTICLE X. MISCELLANEOUS......................................................43
     Section 10.1.     Trust Indenture Act Controls...........................43
     Section 10.2.     Notices................................................43
     Section 10.3.     Communication by Holders with Other Holders............44


                                       ii
<PAGE>

     Section 10.4.     Certificate and Opinion as to Conditions Precedent.....44
     Section 10.5.     Statements Required in Certificate or Opinion..........45
     Section 10.6.     Rules by Trustee and Agents............................45
     Section 10.7.     Legal Holidays.........................................45
     Section 10.8.     No Personal Liability of Directors, Officers,
                       Employees and Stockholders.............................45
     Section 10.9.     Counterparts...........................................46
     Section 10.10.    Governing Laws.........................................46
     Section 10.11.    No Adverse Interpretation of Other Agreements..........46
     Section 10.12.    Successors.............................................46
     Section 10.13.    Severability...........................................46
     Section 10.14.    Table of Contents, Headings, Etc.......................46
     Section 10.15.    Securities in a Foreign Currency or in ECU.............46
     Section 10.16.    Judgment Currency......................................47
ARTICLE XI. SINKING FUNDS.....................................................48
     Section 11.1.     Applicability of Article...............................48
     Section 11.2.     Satisfaction of Sinking Fund Payments with Securities..48
     Section 11.3.     Redemption of Securities for Sinking Fund..............49
ARTICLE XII. SUBSIDIARY GUARANTEES............................................49
     Section 12.1.     Subsidiary Guarantee...................................49
     Section 12.2.     Limitation of Guarantor's Liability....................51
ARTICLE XIII. SUBORDINATION...................................................51
     Section 13.1.     Agreement to Subordinate...............................51
     Section 13.2.     Liquidation; Dissolution; Bankruptcy...................51
     Section 13.3.     Default on Designated Senior Debt......................52
     Section 13.4.     Acceleration of Securities.............................53
     Section 13.5.     When Distribution Must be Paid Over....................53
     Section 13.6.     Notice By Company......................................53
     Section 13.7.     Subrogation............................................54
     Section 13.8.     Relative Rights........................................54
     Section 13.9.     Subordination May Not Be Impaired by Company...........54
     Section 13.10.    Distribution or Notice to Representative...............54
     Section 13.11.    Rights of Trustee and Paying Agent.....................55
     Section 13.12.    Authorization to Effect Subordination..................55
     Section 13.13.    Amendments.............................................55
     Section 13.14.    Subordination of Subsidiary Guarantees.................55
     Section 13.15.    Liquidation; Dissolution; Bankruptcy of a Guarantor....56
     Section 13.16.    Default on Senior Debt of the Guarantor................56
     Section 13.17.    Acceleration of Securities; Duties of Guarantors.......57
     Section 13.18.    When Distribution from Guarantor Must Be Paid Over.....57
     Section 13.19.    Notice by a Guarantor..................................58
     Section 13.20.    Subrogation with Respect to Any Guarantor..............58
     Section 13.21.    Relative Rights with Respect to Any Guarantor..........58
     Section 13.22.    Subordination May Not Be Impaired By Any Guarantor.....58
     Section 13.23.    Distribution or Notice to Representative with Respect
                       to Any Guarantor.......................................59
</TABLE>


                                      iii
<PAGE>

     Section 13.24.    Rights of Trustee and Paying Agent with Respect to
                       Any Guarantor..........................................59
     Section 13.25.    Authorization to Effect Subordination with Respect
                       to Any Guarantor.......................................59
     Section 13.26.    Amendments with Respect to Any Guarantor...............60


                                       iv
<PAGE>

                                                                  EXECUTION COPY

                           IRON MOUNTAIN INCORPORATED

         Reconciliation and tie between Trust Indenture Act of 1939 and
                      Indenture, dated as of April 3, 2001

<TABLE>
<S>                                                                   <C>
Section 310(a)(1)     ...........................................     7.10
           (a)(2)     ...........................................     7.10
           (a)(3)     ...........................................     Not Applicable
           (a)(4)     ...........................................     Not Applicable
           (a)(5)     ...........................................     7.10
           (b)        ...........................................     7.10
Section 310(c)        ...........................................     Not Applicable
Section 311(a)        ...........................................     7.11
           (b)        ...........................................     7.11
           (c)        ...........................................     Not Applicable
Section 312(a)        ...........................................     2.6
           (b)        ...........................................     10.3
           (c)        ...........................................     10.3
Section 313(a)        ...........................................     7.6
           (b)(1)     ...........................................     7.6
           (b)(2)     ...........................................     7.6
           (c)(1)     ...........................................     7.6
           (c)(2)     ...........................................     7.6
           (c)(3)     ...........................................     7.6
           (d)        ...........................................     7.6
Section 314(a)        ...........................................     4.2, 4.3, 10.5
          (b)         ...........................................     Not Applicable
       (c)(1)         ...........................................     10.4
       (c)(2)         ...........................................     10.4
       (c)(3)         ...........................................     Not Applicable
          (d)         ...........................................     Not Applicable
          (e)         ...........................................     10.5
          (f)         ...........................................     Not Applicable
Section 315(a)        ...........................................     7.1(b)
          (b)         ...........................................     7.5
          (c)         ...........................................     7.1
          (d)         ...........................................     7.1
          (e)         ...........................................     6.14
Section 316(a)        ...........................................     2.10
    (a)(1)(A)         ...........................................     6.12
    (a)(1)(B)         ...........................................     6.13
          (b)         ...........................................     6.8
Section 316(c)        ...........................................     2.14
Section 317(a)(1)     ...........................................     6.3
       (a)(2)         ...........................................     6.4
          (b)         ...........................................     2.5


                                       v
<PAGE>

Section 318(a)        ...........................................     10.1
           (b)        ...........................................     Not Applicable
           (c)        ...........................................     Not Applicable
</TABLE>

--------------
Note: This reconciliation and tie shall not, for any purpose, be deemed to be
part of the Indenture.


                                       vi
<PAGE>

                                                                  EXECUTION COPY

            Subordinated Indenture dated as of April 3, 2001 among Iron Mountain
Incorporated, a Pennsylvania corporation ("Company"), the guarantor signatories
hereto and The Bank of New York, a New York banking corporation, as Trustee
("Trustee").

            Each party agrees as follows for the benefit of the other party and
for the equal and ratable benefit of the Holders of the Securities issued under
this Indenture.

                                   ARTICLE I.
                   DEFINITIONS AND INCORPORATION BY REFERENCE

      Section 1.1. Definitions.

            "Additional Amounts" means any additional amounts which are required
hereby or by any Security, under circumstances specified herein or therein, to
be paid by the Company in respect of certain taxes imposed on Holders specified
therein and which are owing to such Holders.

            "Affiliate" of any specified Person means any other Person directly
or indirectly controlling or controlled by or under direct or indirect common
control with such specified Person. For purposes of this definition, "control"
(including, with correlative meanings, the terms "controlling", "controlled by"
and "under common control with"), as used with respect to any Person, shall mean
the possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of such Person, whether through the
ownership of voting securities or by agreement or otherwise; provided, however,
that beneficial ownership of 10% or more of the voting securities of a Person
shall be deemed to be control.

            "Agent" means any Registrar, Paying Agent or Service Agent.

            "Authorized Newspaper" means a newspaper in an official language of
the country of publication customarily published at least once a day for at
least five days in each calendar week and of general circulation in the place in
connection with which the term is used. If it shall be impractical in the
opinion of the Trustee to make any publication of any notice required hereby in
an Authorized Newspaper, any publication or other notice in lieu thereof that is
made or given by the Trustee shall constitute a sufficient publication of such
notice.

            "Bearer Security" means any Security, including any interest coupon
appertaining thereto, that does not provide for the identification of the Holder
thereof.

            "Board of Directors" means the Board of Directors of the Company or
any duly authorized committee thereof.

            "Board Resolution" means a copy of a resolution certified by the
Secretary or an Assistant Secretary of the Company to have been adopted by the
Board of Directors or pursuant to authorization by the Board of Directors and to
be in full force and effect on the date of the certificate and delivered to the
Trustee.

            "Business Day" means, unless otherwise provided by Board Resolution,
Officers' Certificate or supplemental indenture hereto for a particular Series,
any day except a Saturday,

<PAGE>

Sunday or a legal holiday in The City of New York or at a place of payment on
which banking institutions are authorized or required by law, regulation or
executive order to close.

            "Capital Lease Obligation" means, at the time any determination
thereof is to be made, the amount of the liability in respect of a capital lease
that would at such time be so required to be capitalized on the balance sheet in
accordance with GAAP.

            "Capital Stock" means any and all shares, interests, participations,
rights or other equivalents (however designated) of corporate stock, including,
without limitation, with respect to partnerships, partnership interests (whether
general or limited) and any other interest or participation that confers on a
Person the right to receive a share of the profits and losses of, or
distributions of assets of, such partnership.

            "Company" means the party named as such above until a successor
replaces it and thereafter means the successor.

            "Company Order" means a written order signed in the name of the
Company by two Officers.

            "Corporate Trust Office" means the principal office of the Trustee
at which at any time its corporate trust business shall be administered, which
office at the date hereof is located at 101 Barclay Street, Floor 21 West, New
York, New York 10286, Attention: Corporate Trust Administration, or such other
address as the Trustee may designate from time to time by notice to the Holders
and the Company, or the principal corporate trust office of any successor
Trsutee (or such other address as a successor Trustee may designate from time to
time by notice to the Holders and the Company).

            "Credit Agent" means The Chase Manhattan Bank, in its capacity as
administrative agent for the lenders party to the Credit Agreement, and The
Chase Manhattan Bank Canada, in its capacity as Canadian administrative agent
for the lenders party to the Credit Agreement, or any successor or successors
party thereto.

            "Credit Agreement" means that certain Fourth Amended and Restated
Credit Agreement dated as of August 14, 2000, as amended, among the Company,
Iron Mountain Canada Corporation, the lenders party thereto and the Credit
Agent, as further amended, restated, supplemented, modified, renewed, refunded,
increased, extended, replaced or refinanced from time to time.

            "Default" means any event that is or with the passage of time or the
giving of notice or both would be an Event of Default.

            "Depository" means, with respect to the Securities of any Series
issuable or issued in whole or in part in the form of one or more Global
Securities, the Person designated as Depository for such Series by the Company,
which Depository shall be a clearing agency registered under the Exchange Act;
and if at any time there is more than one such Person, "Depository" as used with
respect to the Securities of any Series shall mean the Depository with respect
to the Securities of such Series.


                                       2
<PAGE>

            "Designated Senior Debt" means (a) Senior Bank Debt and (b) other
Senior Debt the principal amount of which is $50.0 million or more at the date
of designation by the Company in a written instrument delivered to the Trustee;
provided that Senior Debt designated as Designated Senior Debt pursuant to
clause (b) shall cease to be Designated Senior Debt at any time that the
aggregate principal amount thereof outstanding is $10.0 million or less.

            "Discount Security" means any Security that provides for an amount
less than the stated principal amount thereof to be due and payable upon
declaration of acceleration of the maturity thereof pursuant to Section 6.2.

            "Disqualified Stock" means any Capital Stock which, by its terms (or
by the terms of any security into which it is convertible or for which it is
exchangeable), or upon the happening of any event, matures or is mandatorily
redeemable, for cash or other property (other than Capital Stock that is not
Disqualified Stock) pursuant to a sinking fund obligation or otherwise, or is
redeemable at the option of the Securityholder thereof, in whole or in part, in
each case on or prior to the stated maturity of the Securities.

            "Dollars" and "$" mean lawful money of the United States of America.

            "ECU" means the European Currency Unit as determined by the
Commission of the European Union.

            "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

            "Existing Senior Subordinated Securities" means (i) the 11-1/8%
Senior Subordinated Notes due 2006 of the Company in an aggregate original
principal amount of US$200,000,000 issued pursuant to the Senior Subordinated
Notes Indenture, dated as of July 15, 1996, between the Company and United
States Trust Company of New York, as trustee, (ii) the 10-1/8% Senior
Subordinated Notes due 2006 of the Company in the aggregate principal amount of
US$165,000,000 issued pursuant to the Senior Subordinated Notes Indenture, dated
as of October 1, 1996 between the Company and First Bank National Association,
as trustee, (iii) the 9-1/8% Senior Subordinated Notes due 2007 of the Company
in an aggregate principal amount of US$120,000,000 issued pursuant to the Senior
Subordinated Notes Indenture, dated as of July 7, 1997 between the Company and
The Bank of New York, as trustee, (iv) the 8-3/4% Senior Subordinated Notes due
2009 of the Company in an aggregate original principal amount of US$250,000,000
issued pursuant to the Senior Subordinated Notes Indenture dated as of October
24, 1997 between the Company and The Bank of New York, as trustee, (v) the
8-1/4% Senior Subordinated Notes due 2011 of the Company in the aggregate
original principal amount of US$150,000,000 issued pursuant to the Senior
Subordinated Notes Indenture dated as of April 26, 1999 between the Company and
the Bank of New York, as trustee, and (vi) the 8 1/8% Senior Notes due 2008 of
Iron Mountain Canada Corporation, the Company's wholly owned Subsidiary, in the
aggregate original principal amount of $135,000,000 issued pursuant to the
Senior Notes Indenture dated as of April 7, 1998, by and among Iron Mountain
Canada Corporation, as issuer, the Company and The Bank of New York, as trustee
(the 8 1/8% Senior Notes have been guaranteed by the Company and certain of its
Subsidiaries (including, without limitation, the Guarantors) on a senior
subordinated basis).


                                       3
<PAGE>

            "Foreign Currency" means any currency or currency unit issued by a
government other than the government of the United States of America.

            "GAAP" means generally accepted accounting principles set forth in
the opinions and pronouncements of the Accounting Principles Board of the
American Institute of Certified Public Accountants and statements and
pronouncements of the Financial Accounting Standards Board or in such other
statements by such other entity as have been approved by a significant segment
of the accounting profession, which are in effect on the date of this Indenture.

            "Global Security" or "Global Securities" means a Security or
Securities, as the case may be, in the form established pursuant to Section 2.2
evidencing all or part of a Series of Securities, issued to the Depository for
such Series or its nominee, and registered in the name of such Depository or
nominee.

            "Government Securities" means direct obligations of, or obligations
guaranteed by, the United States of America for the payment of which guarantee
or obligations the full faith and credit of the United States of America is
pledged.

            "Guarantee" means, as applied to any obligation, (a) a guarantee
(other than by endorsement of negotiable instruments for collection in the
ordinary course of business), direct or indirect, in any manner, of any part or
all of such obligation and (b) an agreement, direct or indirect, contingent or
otherwise, the practical effect of which is to assure in any way the payment or
performance (or payment of damages in the event of non-performance) of all or
any part of such obligation, including, without limiting the foregoing, the
obligation to reimburse amounts drawn down under letters of credit securing such
obligations.

            "Hedging Obligations" means, with respect to any Person, the
obligations of such Person under (a) interest rate swap agreements, interest
rate cap agreements and interest rate collar agreements and (b) other agreements
or arrangements designed to protect such Person against fluctuations in interest
rates.

            "Holder" or "Securityholder" means a Person in whose name a Security
is registered or the holder of a Bearer Security.

            "Indebtedness" means (without duplication), with respect to any
Person, whether recourse is to all or a portion of the assets of such Person,
and whether or not contingent, (a) every obligation of such Person for money
borrowed, (b) every obligation of such Person evidenced by bonds, debentures,
notes or other similar instruments, (c) every reimbursement obligation of such
Person with respect to letters of credit, bankers' acceptances or similar
facilities issued for the account of such Person, (d) every obligation of such
Person issued or assumed as the deferred purchase price of property or services,
(e) every Capital Lease Obligation and every obligation of such Person in
respect of Sale and Leaseback Transactions that would be required to be
capitalized on the balance sheet in accordance with GAAP, (f) all Disqualified
Stock of such Person valued at the greater of its voluntary or involuntary
maximum fixed repurchase price, plus accrued and unpaid dividends (unless
included in such maximum repurchase price), (g) all obligations of such Person
under or with respect to Hedging Obligations which would be required to be
reflected on the balance sheet as a liability of such


                                       4
<PAGE>

Person in accordance with GAAP and (h) every obligation of the type referred to
in clauses (a) through (g) of another Person and dividends of another Person the
payment of which, in either case, such Person has guaranteed. For purposes of
this definition, the "maximum fixed repurchase price" of any Disqualified Stock
that does not have a fixed repurchase price will be calculated in accordance
with the terms of such Disqualified Stock as if such Disqualified Stock were
repurchased on any date on which Indebtedness is required to be determined
pursuant to this Indenture, and if such price is based upon, or measured by, the
fair market value of such Disqualified Stock, such fair market value will be
determined in good faith by the board of directors of the issuer of such
Disqualified Stock. Notwithstanding the foregoing, trade accounts payable and
accrued liabilities arising in the ordinary course of business and any liability
for federal, state or local taxes or other taxes owed by such Person will not be
considered Indebtedness for purposes of this definition. The amount outstanding
at any time of any Indebtedness issued with original issue discount is the
aggregate principal amount at maturity of such Indebtedness, less the remaining
unamortized portion of the original issue discount of such Indebtedness at such
time, as determined in accordance with GAAP.

            "Indenture" means this Indenture as amended and supplemented from
time to time and shall include the form and terms of particular Series of
Securities established as contemplated hereunder and any related supplemental
indenture.

            "interest" with respect to any Discount Security which by its terms
bears interest only after Maturity, means interest payable after Maturity.

            "Maturity," when used with respect to any Security or installment of
principal thereof, means the date on which the principal of such Security or
such installment of principal becomes due and payable as therein or herein
provided, whether at the Stated Maturity or by declaration of acceleration, call
for redemption, notice of option to elect repayment or otherwise.

            "Obligations" means any principal, interest (including post-petition
interest, whether or not allowed as a claim in any proceeding), penalties, fees,
costs, expenses, indemnifications, reimbursements, damages and other liabilities
payable under or in connection with any Indebtedness.

            "Officer" means the Chairman of the Board, the Chief Executive
Officer, the President, the Chief Operating Officer, the Chief Financial
Officer, any Vice-President, the Treasurer, the Controller, the Secretary, any
Assistant Treasurer or any Assistant Secretary of any Person.

            "Officers' Certificate" means a certificate signed, unless otherwise
specified, by any two of the Chairman of the Board, a Vice Chairman of the
Board, the President, the Chief Financial Officer, the Controller or an
Executive Vice President of the Company, and delivered to the Trustee.

            "Opinion of Counsel" means a written opinion of legal counsel who is
reasonably acceptable to the Trustee. The counsel may be an employee of or
counsel to the Company.


                                       5
<PAGE>

            "Person" means any individual, corporation, limited liability
company, partnership, joint venture, association, joint-stock company, trust,
unincorporated organization, or any government or any agency or political
subdivision thereof.

            "principal" of a Security means the principal of the Security plus,
when appropriate, the premium, if any, on, and any Additional Amounts in respect
of, the Security.

            "Representative" means, for purposes of Article 13, the Credit Agent
or other agent, trustee or representative for any Senior Debt of the Company or
a Guarantor, as the case may be.

            "Responsible Officer" means, when used with respect to the Trustee,
any officer within the corporate trust department of the Trustee, including any
vice president, assistant vice president, assistant secretary, assistant
treasurer, trust officer or any other officer of the Trustee who customarily
performs functions similar to those performed by the persons who at the time
shall be such officers, respectively, or to whom any corporate trust matter is
referred because of such person's knowledge of and familiarity with the
particular subject and who shall have direct responsibility for the
administration of this Indenture.

            "Sale and Leaseback Transaction" means any transaction or series of
related transactions pursuant to which a Person sells or transfers any property
or asset in connection with the leasing, or the resale against installment
payments, of such property or asset to the seller or transferor.

            "SEC" means the United States Securities and Exchange Commission.

            "Securities" means the debentures, notes or other instruments of
Indebtedness of the Company of any Series authenticated and delivered under this
Indenture.

            "Securities Act" means the Securities Act of 1933, as amended.

            "Senior Bank Debt" means all Obligations outstanding under or in
connection with the Credit Agreement (including Guarantees of such Obligations
by Subsidiaries of the Company).

            "Senior Debt" means (a) the Senior Bank Debt and (b) any other
Indebtedness permitted to be incurred by the Company, as the case may be, under
the terms of this Indenture, unless the instrument under which such Indebtedness
is incurred expressly provides that it is on a parity with or subordinated in
right of payment to the Securities or subordinated to Senior Debt on terms
substantially similar to those of the Securities. Notwithstanding anything to
the contrary in the foregoing, Senior Debt shall not include (i) any liability
for federal, state, local or other taxes owed or owing by the Company, (ii) any
Indebtedness of the Company to any of its Subsidiaries or other Affiliates,
(iii) any trade payables or (iv) any Indebtedness that is incurred in violation
of this Indenture provided that such Indebtedness shall be deemed not to have
been incurred in violation of the Indenture for purposes of this clause (iv) if,
in the case of any obligations under the Credit Agreement, the holders of such
obligations or their agent or


                                       6
<PAGE>

representative shall have received a representation from the Company to the
effect that the incurrence of such Indebtedness does not violate the provisions
of this Indenture.

            "Series" or "Series of Securities" means each series of debentures,
notes or other debt instruments of the Company created pursuant to Sections 2.1
and 2.2 hereof.

            "Significant Subsidiary" means any Subsidiary that would be a
"significant subsidiary" as defined in Article 1, Rule 1-02 of Regulation S-X,
promulgated pursuant to the Securities Act, as such regulation is in effect on
the date hereof.

            "Stated Maturity" when used with respect to any Security or any
installment of principal thereof or interest thereon, means the date specified
in such Security as the fixed date on which the principal of such Security or
such installment of principal or interest is due and payable.

            "Subsidiary" means, with respect to any Person, any corporation,
association or other business entity of which more than 50% of the total voting
power of shares of Capital Stock entitled (without regard to the occurrence of
any contingency) to vote in the election of directors, managers or trustees
thereof is at the time owned or controlled, directly or indirectly, by such
Person or one or more of the other Subsidiaries of such Person or a combination
thereof.

            "Subsidiary Guarantee" means a Guarantee of a Guarantor pursuant to
Article XII hereof.

            "TIA" means the Trust Indenture Act of 1939 (15 U.S. Code
Sections 77aaa-77bbbb) as in effect on the date of this Indenture; provided,
however, that in the event the Trust Indenture Act of 1939 is amended after
such date, "TIA" means, to the extent required by any such amendment, the
Trust Indenture Act as so amended.

            "Trustee" means the Person named as the "Trustee" in the first
paragraph of this instrument until a successor Trustee shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Trustee" shall mean or include each Person who is then a Trustee hereunder, and
if at any time there is more than one such Person, "Trustee" as used with
respect to the Securities of any Series shall mean the Trustee with respect to
Securities of that Series.

      Section 1.2. Other Definitions.

<TABLE>
<CAPTION>
TERM                                                                 DEFINED IN
----                                                                   SECTION
                                                                       -------

<S>                                                                  <C>
"Bankruptcy Law"                                                          6.1
"Benefited Party"                                                        12.1
"Covenant Defeasance"                                                     8.2
"Custodian"                                                               6.1
"Event of Default"                                                        6.1
"Guarantor"                                                              12.1


                                       7
<PAGE>

"Journal"                                                                10.15
"Judgment Currency"                                                      10.16
"Legal Defeasance"                                                        8.2
"Legal Holiday"                                                          10.7
"mandatory sinking fund payment"                                         11.1
"Market Exchange Rate"                                                   10.15
"New York Banking Day"                                                   10.16
"Non-Monetary Default                                                    13.3
"Notice of Default"                                                       6.1
"optional sinking fund payment"                                          11.1
"Paying Agent"                                                            2.4
"Payment Blockage Notice"                                                13.3
"Payment Default"                                                        13.3
"Registrar"                                                               2.4
"Required Currency"                                                      10.16
"Service Agent"                                                           2.4
"Successor Person"                                                        5.1
</TABLE>

      Section 1.3. Incorporation by Reference of Trust Indenture Act.

            Whenever this Indenture refers to a provision of the TIA, the
provision is incorporated by reference in and made a part of this Indenture. The
following TIA terms used in this Indenture have the following meanings:

            "Commission" means the SEC.

            "indenture securities" means the Securities and the Subsidiary
            Guarantees, if any.

            "indenture security holder" means a Holder or a Securityholder.

            "indenture to be qualified" means this Indenture.

            "indenture trustee" or "institutional trustee" means the Trustee.

            "obligor" on the indenture securities means the Company, the
            Guarantors, if any, and any successor obligor upon the Securities or
            any Subsidiary Guarantee, as the case may be.

            All other terms used in this Indenture that are defined by the TIA,
defined by TIA reference to another statute or defined by SEC rule under the TIA
and not otherwise defined herein are used herein as so defined.

      Section 1.4. Rules of Construction.

            Unless the context otherwise requires:

            (a) a term has the meaning assigned to it;


                                       8
<PAGE>

            (b) an accounting term not otherwise defined has the meaning
      assigned to it in accordance with GAAP;

            (c) "or" is not exclusive;

            (d) words in the singular include the plural, and in the plural
      include the singular;

            (e) provisions apply to successive events and transactions; and

            (f) references to sections of or rules under the Securities Act or
      the Exchange Act shall be deemed to include substitute, replacement or
      successor sections or rules adopted by the SEC from time to time.

                                  ARTICLE II.
                                 THE SECURITIES

      Section 2.1. Issuable in Series.

            The aggregate principal amount of Securities that may be
authenticated and delivered under this Indenture is unlimited. The Securities
may be issued in one or more Series. All Securities of a Series shall be
identical except as may be set forth in a Board Resolution, a supplemental
indenture or an Officers' Certificate detailing the adoption of the terms
thereof pursuant to the authority granted under a Board Resolution. In the case
of Securities of a Series to be issued from time to time, the Board Resolution,
Officers' Certificate or supplemental indenture may provide for the method by
which specified terms (such as interest rate, maturity date, record date or date
from which interest shall accrue) are to be determined. Securities may differ
between Series in respect of any matters, provided that all Series of Securities
shall be equally and ratably entitled to the benefits of the Indenture.

      Section 2.2. Establishment of Terms of Series of Securities.

            At or prior to the issuance of any Securities within a Series, the
following shall be established (as to the Series generally, in the case of
Subsection 2.2.1 and either as to such Securities within the Series or as to the
Series generally in the case of Subsections 2.2.2 through 2.2.21) by a Board
Resolution, a supplemental indenture or an Officers' Certificate pursuant to
authority granted under a Board Resolution:

            2.2.1. the title of the Series (which shall distinguish the
Securities of that particular Series from the Securities of any other Series);

            2.2.2. the price or prices (expressed as a percentage of the
principal amount thereof) at which the Securities of the Series will be issued;

            2.2.3. any limit upon the aggregate principal amount of the
Securities of the Series which may be authenticated and delivered under this
Indenture (except for Securities


                                       9
<PAGE>

authenticated and delivered upon registration of transfer of, or in exchange
for, or in lieu of, other Securities of the Series pursuant to Section 2.7, 2.8,
2.11, 3.6 or 9.6, or any applicable provision of a supplemental indenture);

            2.2.4. the date or dates on which the principal of the Securities of
the Series is payable;

            2.2.5. the rate or rates (which may be fixed or variable) per annum
or, if applicable, the method used to determine such rate or rates (including,
but not limited to, any commodity, commodity index, stock exchange index or
financial index) at which the Securities of the Series shall bear interest, if
any, the date or dates from which such interest, if any, shall accrue, the date
or dates on which such interest, if any, shall commence and be payable and any
regular record date for the interest payable on any interest payment date;

            2.2.6. the place or places where the principal of and interest, if
any, on the Securities of the Series shall be payable, or the method of such
payment, if by wire transfer, mail or other means;

            2.2.7. if applicable, the period or periods within which, the price
or prices at which and the terms and conditions upon which the Securities of the
Series may be redeemed, in whole or in part, at the option of the Company;

            2.2.8. the obligation, if any, of the Company to redeem or purchase
the Securities of the Series pursuant to any sinking fund or analogous
provisions or at the option of a Holder thereof and the period or periods within
which, the price or prices at which and the terms and conditions upon which
Securities of the Series shall be redeemed or purchased, in whole or in part,
pursuant to such obligation;

            2.2.9. the dates, if any, on which and the price or prices at which
the Securities of the Series will be repurchased by the Company at the option of
the Holders thereof and other detailed terms and provisions of such repurchase
obligations;

            2.2.10. if other than denominations of $1,000 and any integral
multiple thereof, the denominations in which the Securities of the Series shall
be issuable;

            2.2.11. the forms of the Securities of the Series in bearer or fully
registered form (and, if in fully registered form, whether the Securities will
be issuable as Global Securities);

            2.2.12. if other than the principal amount thereof, the portion of
the principal amount of the Securities of the Series that shall be payable upon
declaration of acceleration of the maturity thereof pursuant to Section 6.2;

            2.2.13. the currency of denomination of the Securities of the
Series, which may be Dollars or any Foreign Currency, including, but not limited
to, the ECU, and if such currency of denomination is a composite currency other
than the ECU, the agency or organization, if any, responsible for overseeing
such composite currency;


                                       10
<PAGE>

            2.2.14. the designation of the currency, currencies or currency
units in which payment of the principal of and interest, if any, on the
Securities of the Series will be made;

            2.2.15. if payments of principal of or interest, if any, on the
Securities of the Series are to be made in one or more currencies or currency
units other than that or those in which such Securities are denominated, the
manner in which the exchange rate with respect to such payments will be
determined;

            2.2.16. the manner in which the amounts of payment of principal of
or interest, if any, on the Securities of the Series will be determined, if such
amounts may be determined by reference to an index based on a currency or
currencies or by reference to a commodity, commodity index, stock exchange index
or financial index;

            2.2.17. the provisions, if any, relating to any security provided
for the Securities of the Series;

            2.2.18. any addition to or change in the Events of Default which
applies to any Securities of the Series and any change in the right of the
Trustee or the requisite Holders of such Securities to declare the principal
amount thereof due and payable pursuant to Section 6.2;

            2.2.19. any addition to or change in the covenants set forth in
Articles IV or V which applies to Securities of the Series;

            2.2.20. any other terms of the Securities of the Series (which may
modify or delete any provision of this Indenture insofar as it applies to such
Series); and

            2.2.21. any depositories, interest rate calculation agents, exchange
rate calculation agents or other agents with respect to Securities of such
Series if other than those appointed herein.

            All Securities of any one Series need not be issued at the same time
and may be issued from time to time, consistent with the terms of this
Indenture, if so provided by or pursuant to the Board Resolution, supplemental
indenture or Officers' Certificate referred to above, and the authorized
principal amount of any Series may not be increased to provide for issuances of
additional Securities of such Series, unless otherwise provided in such Board
Resolution, supplemental indenture or Officers' Certificate.

      Section 2.3. Execution and Authentication.

            Two Officers shall sign the Securities for the Company by manual or
facsimile signature. An Officer of each Guarantor shall sign the Subsidiary
Guarantee for the Guarantor by manual or facsimile signature.

            If an Officer whose signature is on a Security or Subsidiary
Guarantee no longer holds that office at the time the Security is authenticated,
the Security or Subsidiary Guarantee shall nevertheless be valid.


                                       11
<PAGE>

            A Security shall not be valid until authenticated by the manual
signature of the Trustee or an authenticating agent. Such signature shall be
conclusive evidence that the Security has been authenticated under this
Indenture.

            The Trustee shall at any time, and from time to time, authenticate
Securities for original issue in the principal amount provided in the Board
Resolution, supplemental indenture hereto or Officers' Certificate, upon receipt
by the Trustee of a Company Order. Such Company Order may authorize
authentication and delivery pursuant to oral or electronic instructions from the
Company or its duly authorized agent or agents, which oral instructions shall be
promptly confirmed in writing. Each Security shall be dated the date of its
authentication unless otherwise provided by a Board Resolution, a supplemental
indenture hereto or an Officers' Certificate.

            The aggregate principal amount of Securities of any Series
outstanding at any time may not exceed any limit upon the maximum principal
amount for such Series set forth in the Board Resolution, supplemental indenture
hereto or Officers' Certificate delivered pursuant to Section 2.2, except as
provided in Section 2.8.

            Prior to the issuance of Securities of any Series, the Trustee shall
have received and (subject to Section 7.2) shall be fully protected in relying
on: (a) the Board Resolution, supplemental indenture hereto or Officers'
Certificate establishing the form of the Securities of that Series or of
Securities within that Series and the terms of the Securities of that Series or
of Securities within that Series, (b) an Officers' Certificate complying with
Section 10.4, and (c) an Opinion of Counsel complying with Section 10.4.

            The Trustee shall have the right to decline to authenticate and
deliver any Securities of such Series: (a) if the Trustee, being advised by
counsel, determines that such action may not lawfully be taken; or (b) if the
Trustee in good faith by its board of directors or trustees, executive committee
or a trust committee of directors and/or vice-presidents shall determine that
such action would expose the Trustee to personal liability to Holders of any
then outstanding Series of Securities.

            The Trustee may appoint an authenticating agent acceptable to the
Company to authenticate Securities. Unless limited by the terms of such
appointment, an authenticating agent may authenticate Securities whenever the
Trustee may do so. Each reference in this Indenture to authentication by the
Trustee includes authentication by such agent. An authenticating agent has the
same rights as an Agent to deal with the Company or an Affiliate.

      Section 2.4. Registrar and Paying Agent.

            The Company shall maintain, with respect to each Series of
Securities, at the place or places specified with respect to such Series
pursuant to Section 2.2, an office or agency where Securities of such Series may
be presented or surrendered for payment ("Paying Agent"), where Securities of
such Series may be surrendered for registration of transfer or exchange
("Registrar") and where notices and demands to or upon the Company in respect of
the Securities of such Series and this Indenture may be served ("Service
Agent"). The Registrar shall keep a register with respect to each Series of
Securities and to their transfer and exchange. The Company will give prompt
written notice to the Trustee of the name and address, and any


                                       12
<PAGE>

change in the name or address, of each Registrar, Paying Agent or Service Agent.
If at any time the Company shall fail to maintain any such required Registrar,
Paying Agent or Service Agent or shall fail to furnish the Trustee with the name
and address thereof, such presentations, surrenders, notices and demands may be
made or served at the Corporate Trust Office of the Trustee, and the Company
hereby appoints the Trustee as its agent to receive all such presentations,
surrenders, notices and demands.

            The Company may also from time to time designate one or more
co-registrars, additional paying agents or additional service agents and may
from time to time rescind such designations; provided, however, that no such
designation or rescission shall in any manner relieve the Company of its
obligations to maintain a Registrar, Paying Agent and Service Agent in each
place so specified pursuant to Section 2.2 for Securities of any Series for such
purposes. The Company will give prompt written notice to the Trustee of any such
designation or rescission and of any change in the name or address of any such
co-registrar, additional paying agent or additional service agent. The term
"Registrar" includes any co-registrar; the term "Paying Agent" includes any
additional paying agent; and the term "Service Agent" includes any additional
service agent. The Company or any Guarantor may act as Paying Agent, Registrar
or Service Agent. The Company shall enter into an appropriate agency agreement
with any Agent not a party to this Indenture, which shall be subject to any
obligations imposed by the provisions of the TIA. The agreement shall implement
the provisions of this Indenture that relate to such Agent.

            The Company hereby appoints the Trustee the initial Registrar,
Paying Agent and Service Agent for each Series unless another Registrar, Paying
Agent or Service Agent, as the case may be, is appointed prior to the time
Securities of that Series are first issued.

      Section 2.5. Paying Agent to Hold Money in Trust.

            The Company shall require each Paying Agent other than the Trustee
to agree in writing that the Paying Agent will hold in trust, for the benefit of
Securityholders of any Series of Securities, or the Trustee, all money held by
the Paying Agent for the payment of principal of or premium, if any, or interest
on the Series of Securities, and will notify the Trustee of any default by the
Company or the Guarantors in making any such payment. While any such default
continues, the Trustee may require a Paying Agent to pay all money held by it to
the Trustee. The Company at any time may require a Paying Agent to pay all money
held by it to the Trustee. Upon payment over to the Trustee, the Paying Agent
(if other than the Company or a Subsidiary) shall have no further liability for
the money delivered to the Trustee. If the Company or a Subsidiary acts as
Paying Agent, it shall segregate and hold in a separate trust fund for the
benefit of Securityholders of any Series of Securities, subject to Article XIII
hereof, all money held by it as Paying Agent.

      Section 2.6. Securityholder Lists.

            The Trustee shall preserve in as current a form as is reasonably
practicable the most recent list available to it of the names and addresses
of Securityholders of each Series of Securities and shall otherwise comply
with TIA Section 312(a). If the Trustee is not the Registrar, the Company
shall furnish to the Trustee at least ten days before each interest payment
date and at

                                       13
<PAGE>

such other times as the Trustee may request in writing a list, in such form and
as of such date as the Trustee may reasonably require, of the names and
addresses of Securityholders of each Series of Securities.

      Section 2.7. Transfer and Exchange.

            Where Securities of a Series are presented to the Registrar or a
co-registrar with a request to register a transfer or to exchange them for an
equal principal amount of Securities of the same Series, the Registrar shall
register the transfer or make the exchange if its requirements for such
transactions are met. To permit registrations of transfers and exchanges, the
Trustee shall authenticate Securities at the Registrar's request. No service
charge shall be made for any registration of transfer or exchange (except as
otherwise expressly permitted herein), but the Company may require payment of a
sum sufficient to cover any transfer tax or similar governmental charge payable
in connection therewith (other than any such transfer tax or similar
governmental charge payable upon exchanges pursuant to Sections 2.11, 3.6 or
9.6).

            Neither the Company nor the Registrar shall be required (a) to
issue, register the transfer of, or exchange Securities of any Series for the
period beginning at the opening of business fifteen days immediately preceding
the mailing of a notice of redemption of Securities of that Series selected for
redemption and ending at the close of business on the day of such mailing, or
(b) to register the transfer of or exchange Securities of any Series selected,
called or being called for redemption as a whole or the portion being redeemed
of any such Securities selected, called or being called for redemption in part.

      Section 2.8. Mutilated, Destroyed, Lost and Stolen Securities.

            If any mutilated Security is surrendered to the Trustee, the Company
shall execute and the Trustee shall authenticate and deliver in exchange
therefor a new Security of the same Series and of like tenor and principal
amount and bearing a number not contemporaneously outstanding.

            If there shall be delivered to the Company and the Trustee (i)
evidence to their satisfaction of the destruction, loss or theft of any Security
and (ii) such security or indemnity as may be required by them to save each of
them and any agent of either of them harmless, then, in the absence of notice to
the Company or the Trustee that such Security has been acquired by a bona fide
purchaser, the Company shall execute and upon its request the Trustee shall
authenticate and make available for delivery, in lieu of any such destroyed,
lost or stolen Security, a new Security of the same Series and of like tenor and
principal amount and bearing a number not contemporaneously outstanding.

            In case any such mutilated, destroyed, lost or stolen Security has
become or is about to become due and payable, the Company in its discretion may,
instead of issuing a new Security, pay such Security.

            Upon the issuance of any new Security under this Section, the
Company may require the payment of a sum sufficient to cover any tax or other
governmental charge that may


                                       14
<PAGE>

be imposed in relation thereto and any other expenses (including the fees and
expenses of the Trustee) connected therewith.

            Every new Security of any Series issued pursuant to this Section in
lieu of any destroyed, lost or stolen Security shall constitute an original
additional contractual obligation of the Company, whether or not the destroyed,
lost or stolen Security shall be at any time enforceable by anyone, and shall be
entitled to all the benefits of this Indenture equally and proportionately with
any and all other Securities of that Series duly issued hereunder.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Securities.

      Section 2.9. Outstanding Securities.

            The Securities outstanding at any time are all the Securities
authenticated by the Trustee except for those canceled by it, those delivered to
it for cancellation, those reductions in the interest on a Global Security
effected by the Trustee in accordance with the provisions hereof and those
described in this Section as not outstanding.

            If a Security is replaced pursuant to Section 2.8, it ceases to be
outstanding until the Trustee receives proof satisfactory to it that the
replaced Security is held by a bona fide purchaser.

            If the Paying Agent (other than the Company, a Subsidiary or an
Affiliate of any thereof) holds on the Maturity of Securities of a Series money
sufficient to pay such Securities payable on that date, then on and after that
date such Securities of the Series cease to be outstanding and interest on them
ceases to accrue.

            A Security does not cease to be outstanding because the Company, a
Guarantor or an Affiliate of the Company or a Guarantor holds the Security.

            In determining whether the Holders of the requisite principal amount
of outstanding Securities have given any request, demand, authorization,
direction, notice, consent or waiver hereunder, the principal amount of a
Discount Security that shall be deemed to be outstanding for such purposes shall
be the amount of the principal thereof that would be due and payable as of the
date of such determination upon a declaration of acceleration of the Maturity
thereof pursuant to Section 6.2.

      Section 2.10. Treasury Securities.

            In determining whether the Holders of the required principal amount
of Securities of a Series have concurred in any request, demand, authorization,
direction, notice, consent or waiver, Securities of a Series owned by the
Company or an Affiliate shall be disregarded, except that for the purposes of
determining whether the Trustee shall be protected in relying on any such
request, demand, authorization, direction, notice, consent or waiver, only
Securities of a Series that a Responsible Officer of the Trustee actually knows
are so owned shall be so disregarded.


                                       15
<PAGE>

Notwithstanding the foregoing, Securities of a Series that are to be acquired by
the Company, any Guarantor, any Subsidiary of the Company or any Guarantor or an
Affiliate of the Company or any Guarantor pursuant to an exchange offer, tender
offer or other agreement shall not be deemed to be owned by the Company, such
Guarantor, a Subsidiary of the Company or such Guarantor or an Affiliate of the
Company or such Guarantor until legal title to such Securities passes to the
Company, such Guarantor, such Subsidiary or such Affiliate, as the case may be.

      Section 2.11. Temporary Securities.

            Until definitive Securities are ready for delivery, the Company may
prepare and the Trustee shall authenticate temporary Securities upon a Company
Order. Temporary Securities shall be substantially in the form of definitive
Securities but may have variations that the Company considers appropriate for
temporary Securities. Without unreasonable delay, the Company shall prepare and
the Trustee upon request shall authenticate definitive Securities of the same
Series and date of maturity in exchange for temporary Securities. Until so
exchanged, temporary securities shall have the same rights under this Indenture
as the definitive Securities.

      Section 2.12. Cancellation.

            The Company at any time may deliver Securities to the Trustee for
cancellation. The Registrar and the Paying Agent shall forward to the Trustee
any Securities surrendered to them for registration of transfer, exchange or
payment. The Trustee shall cancel all Securities surrendered for transfer,
exchange, payment, replacement or cancellation and shall dispose of such
canceled Securities (subject to the record retention requirement of the Exchange
Act) in accordance with the Trustee's customary practice. The Company may not
issue new Securities to replace Securities that it has paid or delivered to the
Trustee for cancellation.

      Section 2.13. Defaulted Interest.

            If the Company and the Guarantors default in a payment of interest
on Series of Securities, the Company or any such Guarantor (to the extent of its
obligations under its Subsidiary Guarantee) shall pay the defaulted interest in
any lawful manner plus, to the extent lawful, interest payable on the defaulted
interest, to the Persons who are Securityholders of the Series on a subsequent
special record date, which date shall be at the earliest practicable date but in
all events at least five Business Days prior to the payment date, in each case
at the rate provided for with respect to the applicable Securities. The Company
shall fix or cause to be fixed each such special record date and payment date,
and shall, promptly thereafter, notify the Trustee of any such date. At least 15
days before the special record date, the Company (or the Trustee, in the name of
and at the expense of the Company) shall mail to Securityholders of the Series a
notice that states the special record date, the related payment date and the
amount of such interest to be paid. The Company and the Guarantors may pay
defaulted interest in any other lawful manner.


                                       16
<PAGE>

      Section 2.14. Record Date.

            The record date for purposes of determining the identity of
Securityholders of the Series entitled to vote or consent to any action by vote
or consent authorized or permitted under this Indenture shall be determined as
provided for in TIA Section 316(c).

      Section 2.15. Global Securities.

            2.15.1. Terms of Securities. A Board Resolution, a supplemental
indenture hereto or an Officers' Certificate shall establish whether the
Securities of a Series shall be issued in whole or in part in the form of one or
more Global Securities and the Depository for such Global Security or
Securities.

            2.15.2. Transfer and Exchange. Notwithstanding any provisions to the
contrary contained in Section 2.7 of the Indenture and in addition thereto, any
Global Security shall be exchangeable pursuant to Section 2.7 of the Indenture
for Securities registered in the names of Holders other than the Depository for
such Security or its nominee only if (i) such Depository notifies the Company
that it is unwilling or unable to continue as Depository for such Global
Security or if at any time such Depository ceases to be a clearing agency
registered under the Exchange Act, and, in either case, the Company fails to
appoint a successor Depository within 90 days of such event, (ii) the Company
executes and delivers to the Trustee an Officers' Certificate to the effect that
such Global Security shall be so exchangeable or (iii) an Event of Default with
respect to the Securities represented by such Global Security shall have
happened and be continuing. Any Global Security that is exchangeable pursuant to
the preceding sentence shall be exchangeable for Securities registered in such
names as the Depository shall direct in writing in an aggregate principal amount
equal to the principal amount of the Global Security with like tenor and terms.

            Except as provided in this Section 2.15.2, a Global Security may not
be transferred except as a whole by the Depository with respect to such Global
Security to a nominee of such Depository, by a nominee of such Depository to
such Depository or another nominee of such Depository or by the Depository or
any such nominee to a successor Depository or a nominee of such a successor
Depository.

            2.15.3. Legend. Any Global Security issued hereunder shall bear a
legend in substantially the following form:

            "This Security is a Global Security within the meaning of the
Indenture hereinafter referred to and is registered in the name of the
Depository or a nominee of the Depository. This Security is exchangeable for
Securities registered in the name of a Person other than the Depository or its
nominee only in the limited circumstances described in the Indenture, and may
not be transferred except as a whole by the Depository to a nominee of the
Depository, by a nominee of the Depository to the Depository or another nominee
of the Depository or by the Depository or any such nominee to a successor
Depository or a nominee of such a successor Depository."


                                       17
<PAGE>

            2.15.4. Acts of Holders. The Depository, as a Holder, may appoint
agents and otherwise authorize participants to give or take any request, demand,
authorization, direction, notice, consent, waiver or other action which a Holder
is entitled to give or take under the Indenture.

            2.15.5. Payments. Notwithstanding the other provisions of this
Indenture, unless otherwise specified as contemplated by Section 2.2, payment of
the principal of and interest, if any, on any Global Security shall be made to
the Holder thereof.

            2.15.6. Consents, Declaration and Directions. Except as provided in
Section 2.15.5, the Company, the Trustee and any Agent shall treat a Person as
the Holder of such principal amount of outstanding Securities of such Series
represented by a Global Security as shall be specified in a written statement of
the Depository with respect to such Global Security, for purposes of obtaining
any consents, declarations, waivers or directions required to be given by the
Holders pursuant to this Indenture.

      Section 2.16. CUSIP Numbers.

            The Company in issuing the Securities may use "CUSIP" numbers (if
then generally in use), and, if so, the Trustee shall use "CUSIP" numbers in
notices of redemption as a convenience to Holders; provided that any such notice
may state that no representation is made as to the correctness of such numbers
either as printed on the Securities or as contained in any notice of a
redemption and that reliance may be placed only on the other identification
numbers printed on the Securities, and any such redemption shall not be affected
by any defect in or omission of such numbers. The Company will promptly notify
the Trustee of any change in the CUSIP number.

                                  ARTICLE III.
                                   REDEMPTION

      Section 3.1. Notice to Trustee.

            The Company may, with respect to any Series of Securities, reserve
the right to redeem and pay the Series of Securities or may covenant to redeem
and pay the Series of Securities or any part thereof prior to the Stated
Maturity thereof at such time and on such terms as provided for in such
Securities. If a Series of Securities is redeemable and the Company wants or is
obligated to redeem prior to the Stated Maturity thereof all or part of the
Series of Securities pursuant to the terms of such Securities, it shall notify
the Trustee of the redemption date and the principal amount of Series of
Securities to be redeemed. The Company shall give the notice at least 45 days
before the redemption date (or such shorter notice as may be acceptable to the
Trustee), which notice shall be in the form of an Officers' Certificate setting
forth (i) the Section of this Indenture pursuant to which the redemption shall
occur, (ii) the redemption date, (iii) the principal amount of Securities of a
Series to be redeemed and (iv) the redemption price.


                                       18
<PAGE>

      Section 3.2. Selection of Securities to be Redeemed.

            If less than all of any Series of Securities are to be redeemed at
any time, the Trustee shall select the Securities of the Series to be redeemed
among the applicable Holders of such Series in compliance with the requirements
of the principal national securities exchange, if any, on which the Securities
are listed or, if the Securities are not so listed, on a pro rata basis, by lot
or in accordance with any other method the Trustee considers fair and
appropriate, provided that no Securities of $1,000 or less shall be redeemed in
part. In the event of partial redemption by lot, the particular Securities to be
redeemed shall be selected, unless otherwise provided herein, not less than 30
nor more than 60 days prior to the redemption date by the Trustee from the
outstanding Securities not previously called for redemption.

            The Trustee shall promptly notify the Company in writing of the
Securities of the Series selected for redemption and, in the case of any
Security selected for partial redemption, the principal amount thereof to be
redeemed. Securities and portions of Securities selected shall be in amounts of
$1,000 or whole multiples of $1,000; except that if all of the Securities of a
Holder are to be redeemed, the entire outstanding amount of Securities held by
such Holder, even if not a multiple of $1,000, shall be redeemed. Except as
provided in the preceding sentence, provisions of this Indenture that apply to
Securities of a Series called for redemption also apply to portions of
Securities of that Series called for redemption.

      Section 3.3. Notice of Redemption.

            Unless otherwise indicated for a particular Series by Board
Resolution, a supplemental indenture hereto or an Officers' Certificate, at
least 30 days but not more than 60 days before a redemption date, the Company
shall mail or cause to be mailed a notice of redemption by first-class mail to
each Holder whose Securities are to be redeemed and if any Bearer Securities are
outstanding, publish on one occasion a notice in an Authorized Newspaper.

            The notice shall identify the Securities of the Series to be
redeemed (including the CUSIP numbers, if any) and shall state:

            (a) the redemption date;

            (b) the redemption price (including accrued interest to, but
      excluding, the redemption date);

            (c) if any Security of the Series called for redemption is being
      redeemed in part, the portion of the principal amount of such Security to
      be redeemed and that, after the redemption date upon surrender of such
      Security, a new Security or Securities in principal amount equal to the
      unredeemed portion shall be issued upon cancellation of the original
      Security;

            (d) the name and address of the Paying Agent;

            (e) that Securities of the Series called for redemption must be
      surrendered to the Paying Agent to collect the redemption price;


                                       19
<PAGE>

            (f) that, unless the Company defaults in the making of such
      redemption payment, interest on Securities of the Series called for
      redemption ceases to accrue on and after the redemption date; and

            (g) any other information as may be required by the terms of the
      particular Series or the Securities of a Series being redeemed.

            At the Company's request, the Trustee shall give the notice of
redemption in the Company's name and at its expense.

      Section 3.4. Effect of Notice of Redemption.

            Once notice of redemption is mailed or published as provided in
Section 3.3, Securities of a Series called for redemption become due and payable
on the redemption date and at the redemption price. A notice of redemption may
not be conditional. On and after the redemption date, unless the Company
defaults in the payment of the redemption price, interest will cease to accrue
on the Securities of a Series called for called for redemption and all rights of
Holders with respect to such Securities will terminate except for the right to
receive payment of the redemption price upon surrender for redemption. Upon
surrender to the Paying Agent, such Securities shall be paid at the redemption
price plus accrued interest to but excluding the redemption date.

      Section 3.5. Deposit of Redemption Price.

            On or before the redemption date, the Company shall deposit with the
Paying Agent money sufficient to pay the redemption price of and accrued
interest, if any, on all Securities to be redeemed on that date. If the Company
complies with the provisions of the preceding sentence, on and after the
redemption date, interest shall cease to accrue on the Securities or the
portions of Securities called for redemption, whether or not such Securities are
presented for payment. If any Security called for redemption shall not be so
paid upon surrender for redemption because of the failure of the Company to
comply with the first sentence of this paragraph, interest shall be paid on the
unpaid principal, from the redemption date until such principal is paid, and to
the extent lawful on any interest not paid on such unpaid principal, in each
case at the rate provided with respect to such Security.

      Section 3.6. Securities Redeemed in Part.

            Upon surrender of a Security that is redeemed in part, the Trustee
shall authenticate for the Holder a new Security of the same Series and the same
maturity equal in principal amount to the unredeemed portion of the Security
surrendered.


                                       20
<PAGE>

                                  ARTICLE IV.
                                    COVENANTS

      Section 4.1. Payment of Principal and Interest.

            The Company covenants and agrees for the benefit of the Holders of
each Series of Securities that it will duly and punctually pay the principal of
and interest, if any, on the Securities of that Series in accordance with the
terms of such Securities and this Indenture.

      Section 4.2. SEC Reports.

            The Company shall deliver to the Trustee within 15 days after it
files them with the SEC copies of the annual reports and of the information,
documents, and other reports (or copies of such portions of any of the foregoing
as the SEC may by rules and regulations prescribe) which the Company is required
to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act. The
Company also shall comply with the other provisions of TIA Section 314(a).
Notwithstanding anything to the contrary contained herein, the Trustee shall
have no duty to review such documents for purposes of determining compliance
with any provisions of this Indenture. Delivery of such reports, information and
documents to the Trustee is for informational purposes only and the Trustee's
receipt of such shall not constitute constructive notice of any information
contained therein or determinable from information contained therein, including
the Company's compliance with any of its covenants hereunder (as to which the
Trustee is entitled to rely exclusively on Officers' Certificates).

      Section 4.3. Compliance Certificate.

            The Company shall deliver to the Trustee, within 90 days after the
end of each fiscal year of the Company, an Officers' Certificate stating that a
review of the activities of the Company and its Subsidiaries during the
preceding fiscal year has been made under the supervision of the signing
Officers with a view to determining whether the Company has kept, observed,
performed and fulfilled its obligations under this Indenture, and further
stating, as to each such Officer signing such certificate, that to the best of
his knowledge the Company has kept, observed, performed and fulfilled each and
every covenant contained in this Indenture and is not in default in the
performance or observance of any of the terms, provisions and conditions hereof
(or, if a Default or Event of Default shall have occurred, describing all such
Defaults or Events of Default of which he may have knowledge).

            The Company will, so long as any of the Securities are outstanding,
deliver to the Trustee, forthwith upon any Officer becoming aware of any Default
or Event of Default, an Officers' Certificate specifying such Default or Event
of Default and what action the Company is taking or proposes to take with
respect thereto.

      Section 4.4. Stay, Extension and Usury Laws.

            Each of the Company and the Guarantors covenants (to the extent that
it may lawfully do so) that it will not at any time insist upon, plead, or in
any manner whatsoever claim or take the benefit or advantage of, any stay,
extension or usury law wherever enacted, now or at


                                       21
<PAGE>

any time hereafter in force, which may affect the covenants or the performance
of this Indenture or the Securities; and each of the Company and the Guarantors
(to the extent it may lawfully do so) hereby expressly waives all benefit or
advantage of any such law and covenants that it will not, by resort to any such
law, hinder, delay or impede the execution of any power herein granted to the
Trustee, but will suffer and permit the execution of every such power as though
no such law has been enacted.

      Section 4.5. Corporate Existence.

            Subject to Article V, the Company will do or cause to be done all
things necessary to preserve and keep in full force and effect its corporate
existence and the corporate, partnership or other existence of each Significant
Subsidiary in accordance with the respective organizational documents of each
Significant Subsidiary and the rights (charter and statutory), licenses and
franchises of the Company and its Significant Subsidiaries; provided, however,
that the Company shall not be required to preserve any such right, license or
franchise, or the corporate, partnership or other existence of any Significant
Subsidiary, if an Officer shall determine that the preservation thereof is no
longer desirable in the conduct of the business of the Company and its
Subsidiaries taken as a whole and that the loss thereof is not adverse in any
material respect to the Holders.

      Section 4.6. Taxes.

            The Company shall, and shall cause each of its Subsidiaries to, pay
prior to delinquency all material taxes, assessments and governmental levies,
except (i) as contested in good faith and by appropriate proceedings or (ii) the
nonpayment of which would not materially adversely affect the business,
condition (financial or otherwise), operations, performance or properties of the
Company and its Subsidiaries, taken as a whole.

      Section 4.7. Maintenance of Office or Agency

            The Company shall maintain in the Borough of Manhattan, the City of
New York, an office or agency (which may be an office of the Trustee or an
affiliate of the Trustee, Registrar or co-registrar) where the Securities of any
Series may be surrendered for registration of transfer or for exchange and where
notices and demands to or upon the Company in respect of such Securities and
this Indenture may be served. The Company shall give prompt written notice to
the Trustee of the location, and any change in the location, of such office or
agency. If at any time the Company shall fail to maintain any such required
office or agency or shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at the
Corporate Trust Office of the Trustee

            The Company may also from time to time designate one or more
other offices or agencies where the Securities of any Series may be presented
or surrendered for any or all such purposes and may from time to time rescind
such designations; provided, however, that no such designation or rescission
shall in any manner relieve the Company of its obligation to maintain an
office or agency in the Borough of Manhattan, the City of New York for such
purposes. The Company shall give prompt written notice to the Trustee of any
such designation or rescission and of any change in the location of any such
other office or agency.

                                       22
<PAGE>

            The Company hereby designates the Corporate Trust Office of the
Trustee as one such office or agency of the Company in accordance with Section
2.4 hereof.

                                   ARTICLE V.
                                   SUCCESSORS

      Section 5.1. When Company May Merge, Etc.

            The Company shall not consolidate with or merge into, or convey,
transfer or lease all or substantially all of its properties and assets to, any
Person (a "Successor Person"), unless:

            (a) the Successor Person (if any) is a corporation, partnership,
      trust or other entity organized and validly existing under the laws of any
      U.S. domestic jurisdiction and expressly assumes the Company's obligations
      on the Securities and under this Indenture pursuant to a supplemental
      indenture in form reasonably acceptable to the Trustee and

            (b) immediately after giving effect to the transaction, no Default
      or Event of Default, shall have occurred and be continuing.

            The Company shall deliver to the Trustee prior to the consummation
of the proposed transaction an Officers' Certificate to the foregoing effect and
an Opinion of Counsel stating that the proposed transaction and such
supplemental indenture comply with this Indenture.

      Section 5.2. Successor Corporation Substituted.

            Upon any consolidation or merger, or any sale, lease, conveyance or
other disposition of all or substantially all of the assets of the Company in
accordance with Section 5.1, the successor corporation formed by such
consolidation or into or with which the Company is merged or to which such sale,
lease, conveyance or other disposition is made shall succeed to, and be
substituted for (so that from and after the date of such consolidation, merger,
sale, lease, conveyance or other disposition, the provisions of this Indenture
referring to the "Company" shall refer instead to the successor corporation and
not to the Company), and may exercise every right and power of, the Company
under this Indenture with the same effect as if such Successor Person has been
named as the Company herein; provided, however, that the predecessor Company in
the case of a sale, lease, conveyance or other disposition shall not be released
from the obligation to pay the principal of and interest, if any, on the
Securities, except in the case of a sale of all the Company's assets that meets
the requirements of Section 5.1 hereof.

                                  ARTICLE VI.
                              DEFAULTS AND REMEDIES

      Section 6.1. Events of Default.

            "Event of Default," wherever used herein with respect to Securities
of any Series, means any one of the following events, unless in the establishing
Board Resolution,


                                       23
<PAGE>

supplemental indenture or Officers' Certificate, it is provided that such Series
shall not have the benefit of said Event of Default:

            (a) default in the payment of any interest on any Security of that
      Series when it becomes due and payable, and continuance of such default
      for a period of 30 days (whether or not prohibited by the subordination
      provisions of Article XIII hereof); or

            (b) default in the payment of the principal or premium of any
      Security of that Series (whether or not prohibited by the subordination
      provisions of Article XIII hereof) when the same becomes due and payable
      at Maturity, upon redemption (including in connection with an offer to
      purchase) or otherwise; or

            (c) default in the deposit of any sinking fund payment, when and as
      due in respect of any Security of that Series; or

            (d) default in the performance or breach of any covenant or warranty
      of the Company or any Guarantor in this Indenture (other than a covenant
      or warranty that has been included in this Indenture solely for the
      benefit of Series of Securities other than that Series), which default
      continues uncured for a period of 60 days after there has been given, by
      registered or certified mail, to the Company by the Trustee or to the
      Company and the Trustee by the Holders of at least 25% in principal amount
      of the outstanding Securities of that Series a written notice specifying
      such default or breach and requiring it to be remedied and stating that
      such notice is a "Notice of Default" hereunder; or

            (e) a default occurs under any mortgage, indenture or instrument
      under which there may be issued or by which there may be secured or
      evidenced any Indebtedness for money borrowed by the Company or any
      Guarantor (or the payment of which is Guaranteed by the Company or any
      Guarantor), whether such Indebtedness or Guarantee now exists or shall be
      created hereafter if (i) such default results in the acceleration of such
      Indebtedness prior to its express maturity or shall constitute a default
      in the payment of such Indebtedness at final maturity of such Indebtedness
      and (ii) the principal amount of such Indebtedness that has been
      accelerated or not paid at maturity, together with the principal amount of
      any other Indebtedness that has been accelerated or not paid at maturity,
      exceeds $10.0 million; or

            (f) the Company or any of the Guarantors that is a Significant
      Subsidiary pursuant to or within the meaning of any Bankruptcy Law:

                  (i) commences a voluntary case,

                  (ii) consents to the entry of an order for relief against it
            in an involuntary case,

                  (iii) consents to the appointment of a Custodian of it or for
            all or substantially all of its property,

                  (iv) makes a general assignment for the benefit of its
            creditors, or


                                       24
<PAGE>

                  (v) admits in writing that it generally is unable to pay its
            debts as the same become due; or

            (g) a court of competent jurisdiction enters an order or decree
      under any Bankruptcy Law that:

                  (i) is for relief against the Company or any of its
            Significant Subsidiaries in an involuntary case,

                  (ii) appoints a Custodian of the Company or any of its
            Significant Subsidiaries or for all or substantially all of its
            property, or

                  (iii) orders the liquidation of the Company or any of its
            Significant Subsidiaries,

      and the order or decree remains unstayed and in effect for 60 days; or

            (h) any other Event of Default provided with respect to Securities
      of that Series, which is specified in a Board Resolution, a supplemental
      indenture hereto or an Officers' Certificate, in accordance with Section
      2.2.18.

            The term "Bankruptcy Law" means title 11, U.S. Code or any similar
federal or state law for the relief of debtors. The term "Custodian" means any
receiver, trustee, assignee, liquidator or similar official under any Bankruptcy
Law.

      Section 6.2. Acceleration of Maturity; Rescission and Annulment.

            If an Event of Default with respect to Securities of any Series at
the time outstanding occurs and is continuing (other than an Event of Default
referred to in Section 6.1(f) or (g)) then in every such case the Trustee or the
Holders of not less than 25% in principal amount of the outstanding Securities
of that Series may declare the principal amount (or, if any Securities of that
Series are Discount Securities, such portion of the principal amount as may be
specified in the terms of such Securities) of and accrued and unpaid interest,
if any, on all of the Securities of that Series to be due and payable
immediately, by a notice in writing to the Company (and to the Trustee if given
by Holders), and upon any such declaration such principal amount (or specified
amount) and accrued and unpaid interest, if any, shall become immediately due
and payable. If an Event of Default specified in Section 6.1(f) or (g) shall
occur, the principal amount (or specified amount) of and accrued and unpaid
interest, if any, on all outstanding Securities shall ipso facto become and be
immediately due and payable without any declaration or other act on the part of
the Trustee or any Holder.

            At any time after such a declaration of acceleration with respect to
any Series has been made and before a judgment or decree for payment of the
money due has been obtained by the Trustee as hereinafter in this Article
provided, the Holders of a majority in principal amount of the outstanding
Securities of that Series, by written notice to the Company and the Trustee, may
rescind and annul such declaration and its consequences if:


                                       25
<PAGE>

            (a) the Company has paid or deposited with the Trustee a sum
      sufficient to pay

                  (i) all overdue interest, if any, on all Securities of that
            Series,

                  (ii) the principal of any Securities of that Series which have
            become due otherwise than by such declaration of acceleration and
            interest thereon at the rate or rates prescribed therefor in such
            Securities,

                  (iii) to the extent that payment of such interest is lawful,
            interest upon any overdue principal and overdue interest at the rate
            or rates prescribed therefor in such Securities, and

                  (iv) all sums paid or advanced by the Trustee hereunder and
            the reasonable compensation, expenses, disbursements and advances of
            the Trustee, its agents and counsel; and

            (b) all Events of Default with respect to Securities of that Series,
      other than the non-payment of the principal of Securities of that Series
      which have become due solely by such declaration of acceleration, have
      been cured or waived as provided in Section 6.13.

            No such rescission shall affect any subsequent Default or impair any
right consequent thereon.

      Section 6.3. Collection of Indebtedness and Suits for Enforcement by
Trustee.

            The Company covenants that if

            (a) default is made in the payment of any interest on any Security
      when such interest becomes due and payable and such default continues for
      a period of 30 days, or

            (b) default is made in the payment of principal of any Security at
      the Maturity thereof, or

            (c) default is made in the deposit of any sinking fund payment when
      and as due by the terms of a Security,

then, the Company will, upon demand of the Trustee, pay to it, for the benefit
of the Holders of such Securities, the whole amount then due and payable on such
Securities for principal and interest and, to the extent that payment of such
interest shall be legally enforceable, interest on any overdue principal or any
overdue interest, at the rate or rates prescribed therefor in such Securities,
and, in addition thereto, such further amount as shall be sufficient to cover
the costs and expenses of collection, including the reasonable compensation,
expenses, disbursements and advances of the Trustee, its agents and counsel.

            If the Company fails to pay such amounts forthwith upon such demand,
the Trustee, in its own name and as trustee of an express trust, may institute a
judicial proceeding for


                                       26
<PAGE>

the collection of the sums so due and unpaid, may prosecute such proceeding to
judgment or final decree and may enforce the same against the Company or any
other obligor upon such Securities and collect the moneys adjudged or deemed to
be payable in the manner provided by law out of the property of the Company or
any other obligor upon such Securities, wherever situated.

            If an Event of Default with respect to any Securities of any Series
occurs and is continuing, the Trustee may in its discretion proceed to protect
and enforce its rights and the rights of the Holders of Securities of such
Series by such appropriate judicial proceedings as the Trustee shall deem most
effectual to protect and enforce any such rights, whether for the specific
enforcement of any covenant or agreement in this Indenture or in aid of the
exercise of any power granted herein, or to enforce any other proper remedy.

      Section 6.4. Trustee May File Proofs of Claim.

            In case of the pendency of any receivership, insolvency,
liquidation, bankruptcy, reorganization, arrangement, adjustment, composition or
other judicial proceeding relative to the Company or any other obligor upon the
Securities or the property of the Company or of such other obligor or their
creditors, the Trustee (irrespective of whether the principal of the Securities
shall then be due and payable as therein expressed or by declaration or
otherwise and irrespective of whether the Trustee shall have made any demand on
the Company for the payment of overdue principal or interest) shall be entitled
and empowered, by intervention in such proceeding or otherwise,

            (a) to file and prove a claim for the whole amount of principal and
      interest owing and unpaid in respect of the Securities and to file such
      other papers or documents as may be necessary or advisable in order to
      have the claims of the Trustee (including any claim for the reasonable
      compensation, expenses, disbursements and advances of the Trustee, its
      agents and counsel) and of the Holders allowed in such judicial
      proceeding, and

            (b) to collect and receive any moneys or other property payable or
      deliverable on any such claims and to distribute the same,

and any custodian, receiver, assignee, trustee, liquidator, sequestrator or
other similar official in any such judicial proceeding is hereby authorized by
each Holder to make such payments to the Trustee and, in the event that the
Trustee shall consent to the making of such payments directly to the Holders, to
pay to the Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any other
amounts due the Trustee under Section 7.7.

            Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the Securities
or the rights of any Holder thereof or to authorize the Trustee to vote in
respect of the claim of any Holder in any such proceeding.


                                       27
<PAGE>

      Section 6.5. Trustee May Enforce Claims Without Possession of Securities.

            All rights of action and claims under this Indenture or the
Securities may be prosecuted and enforced by the Trustee without the possession
of any of the Securities or the production thereof in any proceeding relating
thereto, and any such proceeding instituted by the Trustee shall be brought in
its own name as trustee of an express trust, and any recovery of judgment shall,
after provision for the payment of the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, be for the
ratable benefit of the Holders of the Securities in respect of which such
judgment has been recovered.

      Section 6.6. Application of Money Collected.

            Any money collected by the Trustee pursuant to this Article shall be
applied in the following order, at the date or dates fixed by the Trustee and,
in case of the distribution of such money on account of principal or interest,
upon presentation of the Securities and the notation thereon of the payment if
only partially paid and upon surrender thereof if fully paid:

            First: To the payment of all amounts due the Trustee under Section
7.7;

            Second: to the holders of Senior Debt of the Company or a
Guarantor, as the case may be, to the extent required by Article XIII hereof;

            Third: To the payment of the amounts then due and unpaid for
principal of and interest on the Securities in respect of which or for the
benefit of which such money has been collected, ratably, without preference or
priority of any kind, according to the amounts due and payable on such
Securities for principal and interest, respectively; and

            Fourth: To the Company.

      Section 6.7. Limitation on Suits.

            No Holder of any Security of any Series shall have any right to
institute any proceeding, judicial or otherwise, with respect to this Indenture,
or for the appointment of a receiver or trustee, or for any other remedy
hereunder, unless

            (a) such Holder has previously given written notice to the Trustee
      of a continuing Event of Default with respect to the Securities of that
      Series;

            (b) the Holders of not less than 25% in principal amount of the
      outstanding Securities of that Series shall have made written request to
      the Trustee to institute proceedings in respect of such Event of Default
      in its own name as Trustee hereunder;

            (c) such Holder or Holders have offered to the Trustee indemnity
      satisfactory to it against the costs, expenses and liabilities to be
      incurred in compliance with such request;

            (d) the Trustee for 60 days after its receipt of such notice,
      request and offer of indemnity has failed to institute any such
      proceeding; and



                                       28
<PAGE>

            (e) no direction inconsistent with such written request has been
      given to the Trustee during such 60-day period by the Holders of a
      majority in principal amount of the outstanding Securities of that Series;

it being understood and intended that no one or more of such Holders shall have
any right in any manner whatever by virtue of, or by availing of, any provision
of this Indenture to affect, disturb or prejudice the rights of any other of
such Holders, or to obtain or to seek to obtain priority or preference over any
other of such Holders or to enforce any right under this Indenture, except in
the manner herein provided and for the equal and ratable benefit of all such
Holders.

      Section 6.8. Unconditional Right of Holders to Receive Principal and
Interest.

            Subject to Articles XII and XIII hereof, notwithstanding any other
provision in this Indenture, the Holder of any Security shall have the right,
which is absolute and unconditional, to receive payment of the principal of and
premium and interest, if any, on such Security on the Stated Maturity or Stated
Maturities expressed in such Security (or, in the case of redemption, on the
redemption date) and to institute suit for the enforcement of any such payment,
and such rights shall not be impaired without the consent of such Holder.

      Section 6.9. Restoration of Rights and Remedies.

            If the Trustee or any Holder has instituted any proceeding to
enforce any right or remedy under this Indenture and such proceeding has been
discontinued or abandoned for any reason, or has been determined adversely to
the Trustee or to such Holder, then and in every such case, subject to any
determination in such proceeding, the Company, the Trustee and the Holders shall
be restored severally and respectively to their former positions hereunder and
thereafter all rights and remedies of the Trustee and the Holders shall continue
as though no such proceeding had been instituted.

      Section 6.10. Rights and Remedies Cumulative.

            Except as otherwise provided with respect to the replacement or
payment of mutilated, destroyed, lost or stolen Securities in Section 2.8, no
right or remedy herein conferred upon or reserved to the Trustee or to the
Holders is intended to be exclusive of any other right or remedy, and every
right and remedy shall, to the extent permitted by law, be cumulative and in
addition to every other right and remedy given hereunder or now or hereafter
existing at law or in equity or otherwise. The assertion or employment of any
right or remedy hereunder, or otherwise, shall not prevent the concurrent
assertion or employment of any other appropriate right or remedy.

      Section 6.11. Delay or Omission Not Waiver.

            No delay or omission of the Trustee or of any Holder of any
Securities to exercise any right or remedy accruing upon any Event of Default
shall impair any such right or remedy or constitute a waiver of any such Event
of Default or an acquiescence therein. Every right and remedy given by this
Article or by law to the Trustee or to the Holders may be exercised from


                                       29
<PAGE>

time to time, and as often as may be deemed expedient, by the Trustee or by the
Holders, as the case may be.

      Section 6.12. Control by Holders.

            The Holders of a majority in principal amount of the outstanding
Securities of any Series shall have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the Trustee, or
exercising any trust or power conferred on the Trustee, with respect to the
Securities of such Series, provided that

            (a) such direction shall not be in conflict with any rule of law or
      with this Indenture,

            (b) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such direction, and

            (c) subject to the provisions of Section 6.1, the Trustee shall have
      the right to decline to follow any such direction if the Trustee in good
      faith shall, by a Responsible Officer of the Trustee, determine that the
      proceeding so directed would involve the Trustee in personal liability.

      Section 6.13. Waiver of Past Defaults.

            The Holders of not less than a majority in principal amount of the
outstanding Securities of any Series may on behalf of the Holders of all the
Securities of such Series waive any past Default hereunder with respect to such
Series and its consequences, except a continuing Default or Event of Default in
the payment of the principal of or interest on any Security of such Series
(provided, however, that the Holders of a majority in principal amount of the
outstanding Securities of any Series may rescind an acceleration and its
consequences, including any related payment default that resulted from such
acceleration). Upon any such waiver, such Default shall cease to exist, and any
Event of Default arising therefrom shall be deemed to have been cured, for every
purpose of this Indenture; but no such waiver shall extend to any subsequent or
other Default or impair any right consequent thereon.

      Section 6.14. Undertaking for Costs.

            All parties to this Indenture agree, and each Holder of any Security
by his acceptance thereof shall be deemed to have agreed, that any court may in
its discretion require, in any suit for the enforcement of any right or remedy
under this Indenture, or in any suit against the Trustee for any action taken,
suffered or omitted by it as Trustee, the filing by any party litigant in such
suit of an undertaking to pay the costs of such suit, and that such court may in
its discretion assess reasonable costs, including reasonable attorneys' fees,
against any party litigant in such suit, having due regard to the merits and
good faith of the claims or defenses made by such party litigant; but the
provisions of this Section shall not apply to any suit instituted by the
Trustee, to any suit instituted by any Holder, or group of Holders, holding in
the aggregate more than 10% in principal amount of the outstanding Securities of
any Series, or to any suit instituted by any Holder for the enforcement of the
payment of the principal of or interest on any Security


                                       30
<PAGE>

on or after the Stated Maturity or Stated Maturities expressed in such Security
(or, in the case of redemption, on the redemption date).

                                  ARTICLE VII.
                                     TRUSTEE

      Section 7.1. Duties of Trustee.

            (a) If an Event of Default has occurred and is continuing, the
      Trustee shall exercise the rights and powers vested in it by this
      Indenture and use the same degree of care and skill in their exercise as a
      prudent Person would exercise or use under the circumstances in the
      conduct of such Person's own affairs.

            (b) Except during the continuance of an Event of Default:

                  (i) The Trustee need perform only those duties that are
            specifically set forth in this Indenture and no others.

                  (ii) In the absence of bad faith on its part, the Trustee may
            conclusively rely, as to the truth of the statements and the
            correctness of the opinions expressed therein, upon Officers'
            Certificates or Opinions of Counsel furnished to the Trustee and
            conforming to the requirements of this Indenture; however, in the
            case of any such Officers' Certificates or Opinions of Counsel which
            by any provisions hereof are specifically required to be furnished
            to the Trustee, the Trustee shall examine such Officers'
            Certificates and Opinions of Counsel to determine whether or not
            they conform to the requirements of this Indenture.

            (c) The Trustee may not be relieved from liability for its own
      negligent action, its own negligent failure to act or its own willful
      misconduct, except that:

                  (i) This paragraph does not limit the effect of paragraph (b)
            of this Section.

                  (ii) The Trustee shall not be liable for any error of judgment
            made in good faith by a Responsible Officer, unless it is proved
            that the Trustee was negligent in ascertaining the pertinent facts.

                  (iii) The Trustee shall not be liable with respect to any
            action taken, suffered or omitted to be taken by it with respect to
            Securities of any Series in good faith in accordance with the
            direction of the Holders of a majority in principal amount of the
            outstanding Securities of such Series relating to the time, method
            and place of conducting any proceeding for any remedy available to
            the Trustee, or exercising any trust or power conferred upon the
            Trustee, under this Indenture with respect to the Securities of such
            Series.

            (d) Every provision of this Indenture that in any way relates to the
      Trustee is subject to paragraph (a), (b) and (c) of this Section.


                                       31
<PAGE>

            (e) The Trustee may refuse to perform any duty or exercise any right
      or power unless it receives indemnity satisfactory to it against any loss,
      liability or expense.

            (f) The Trustee shall not be liable for interest on any money
      received by it except as the Trustee may agree in writing with the
      Company. Money held in trust by the Trustee need not be segregated from
      other funds except to the extent required by law.

            (g) No provision of this Indenture shall require the Trustee to risk
      its own funds or otherwise incur any financial liability in the
      performance of any of its duties, or in the exercise of any of its rights
      or powers, if it shall have reasonable grounds for believing that
      repayment of such funds or adequate indemnity against such risk is not
      reasonably assured to it.

            (h) The Paying Agent, the Registrar and any authenticating agent
      shall be entitled to the protections, immunities and standard of care as
      are set forth in paragraphs (a), (b) and (c) of this Section with respect
      to the Trustee.

      Section 7.2. Rights of Trustee.

            (a) The Trustee may conclusively rely on and shall be protected in
      acting or refraining from acting upon any document believed by it to be
      genuine and to have been signed or presented by the proper Person. The
      Trustee need not investigate any fact or matter stated in the document.

            (b) Before the Trustee acts or refrains from acting, it may require
      an Officers' Certificate or an Opinion of Counsel. The Trustee shall not
      be liable for any action it takes or omits to take in good faith in
      reliance on such Officers' Certificate or Opinion of Counsel.

            (c) The Trustee may act through agents and shall not be responsible
      for the misconduct or negligence of any agent appointed with due care. No
      Depository shall be deemed an agent of the Trustee and the Trustee shall
      not be responsible for any act or omission by any Depository.

            (d) The Trustee shall not be liable for any action it takes or omits
      to take in good faith which it believes to be authorized or within its
      rights or powers.

            (e) The Trustee may consult with counsel of its selection and the
      advice of such counsel or any Opinion of Counsel shall be full and
      complete authorization and protection in respect of any action taken,
      suffered or omitted by it hereunder in good faith and in reliance thereon.

            (f) The Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Indenture at the request or
      direction of any of the Holders of Securities unless such Holders shall
      have offered to the Trustee security or indemnity satisfactory to it
      against the costs, expenses and liabilities which might be incurred by it
      in compliance with such request or direction.


                                       32
<PAGE>

            (g) The Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture, note, other evidence of indebtedness or other paper or
      document, but the Trustee, in its discretion, may make such furhter
      inquiry or investigation into such facts or matters as it may see fit and,
      if the Trustee shall determine to make such further inquiry or
      investigation, it shall be entitled to examine the books, records and
      premises of the Company, personally or by agent or attorney at the sole
      cost of the Company and shall incur no liability or additional liability
      of any kind by reason of such inquiry or investigation.

            (h) The Trustee shall not be deemed to have notice of any Default or
      Event of Default unless a Responsible Officer of the Trustee has actual
      knowledge thereof or unless written notice of any event which is in fact
      such a default is given to the Trustee in accordance with Section 10.2.

            (i) The Trustee may request that the Company deliver an Officers'
      Certificate setting forth the names of individuals and/or titles of
      officers authorized at such time to take specified actions pursuant to
      this Indenture, which Officers' Certificate may be signed by any Person
      authorized to sign an Officers' Certificate, including any Person
      specified as so authorized in any such certificate previously delivered
      and not superseded.

      Section 7.3. Individual Rights of Trustee.

            The Trustee in its individual or any other capacity may become the
owner or pledgee of Securities and may otherwise deal with the Company or an
Affiliate with the same rights it would have if it were not Trustee. However, in
the event that the Trustee acquires any conflicting interest it must eliminate
such conflict within 90 days, apply to the SEC for permission to continue as
trustee or resign. Any Agent may do the same with like rights. The Trustee is
also subject to Sections 7.10 and 7.11.

      Section 7.4. Trustee's Disclaimer.

            The Trustee makes no representation as to the validity or adequacy
of this Indenture or the Securities, it shall not be accountable for the
Company's use of the proceeds from the Securities, and it shall not be
responsible for any statement in the Securities other than its authentication.

      Section 7.5. Notice of Defaults.

            If a Default or Event of Default occurs and is continuing with
respect to the Securities of any Series and if it is actually known to a
Responsible Officer of the Trustee, the Trustee shall mail to each
Securityholder of the Securities of that Series and, if any Bearer Securities
are outstanding, publish on one occasion in an Authorized Newspaper, notice of a
Default or Event of Default within 90 days after it occurs or, if later, after a
Responsible Officer of the Trustee has actual knowledge of such Default or Event
of Default. Except in the case of a Default or Event of Default in payment of
principal of or interest on any Security of any Series, the Trustee may withhold
the notice if and so long as its corporate trust committee or a


                                       33
<PAGE>

committee of its Responsible Officers in good faith determines that withholding
the notice is in the interests of Securityholders of that Series.

      Section 7.6. Reports by Trustee to Holders.

            Within 60 days after January 15 in each year, the Trustee shall
transmit by mail to all Securityholders, as their names and addresses appear
on the register kept by the Registrar and, if any Bearer Securities are
outstanding, publish in an Authorized Newspaper, a brief report dated as of
such January 15, in accordance with, and to the extent required under, TIA
Section 313.

            A copy of each report at the time of its mailing to Securityholders
of any Series shall be filed with the SEC and each stock exchange on which the
Securities of that Series are listed. The Company shall promptly notify the
Trustee when Securities of any Series are listed on any stock exchange or any
delisting thereof.

      Section 7.7. Compensation and Indemnity.

            The Company shall pay to the Trustee from time to time such
compensation for its services as the Company and the Trustee shall agree in
writing. The Trustee's compensation shall not be limited by any law on
compensation of a trustee of an express trust. The Company shall reimburse the
Trustee upon request for all reasonable out-of-pocket expenses incurred by it.
Such expenses shall include the reasonable compensation and expenses of the
Trustee's agents and counsel.

            The Company shall indemnify the Trustee or any predecessor Trustee
and their agents (including the cost of defending itself against any claim
(whether asserted by the Company, or any Holder or any other Person)) against
any and all loss, damages, claims, liability or expense, including taxes (other
than taxes based upon, measured by or determined by the income of the Trustee)
incurred by it except as set forth in the next paragraph in the performance of
their duties under this Indenture as Trustee or Agent. The Trustee shall notify
the Company promptly of any claim for which it may seek indemnity. The Company
shall defend the claim and the Trustee shall cooperate in the defense. The
Trustee may have separate counsel and the Company shall pay the reasonable fees
and expenses of such counsel. The Company need not pay for any settlement made
without its consent, which consent shall not be unreasonably withheld. This
indemnification shall apply to officers, directors, employees, shareholders and
agents of the Trustee.

            The Company need not reimburse any expense or indemnify against any
loss or liability incurred by the Trustee or by any officer, director, employee,
shareholder or agent of the Trustee due to its own negligence or bad faith.

            To secure the Company's payment obligations in this Section, the
Trustee shall have a lien prior to the Securities of any Series on all money or
property held or collected by the Trustee, except that held in trust to pay
principal and interest on particular Securities of that Series.


                                       34
<PAGE>

            When the Trustee incurs expenses or renders services after an Event
of Default specified in Section 6.1(f) or (g) (or any comparable provisions set
forth in a supplemental indenture) occurs, the expenses and the compensation for
the services are intended to constitute expenses of administration under any
Bankruptcy Law.

            The Trustee shall comply with the provisions of TIA Section
313(b)(2) to the extent applicable.

            The provisions of this Section shall survive the termination of this
Indenture and the resignation or removal of the Trustee.

      Section 7.8. Replacement of Trustee.

            A resignation or removal of the Trustee and appointment of a
successor Trustee shall become effective only upon the successor Trustee's
acceptance of appointment as provided in this Section.

            The Trustee may resign with respect to the Securities of one or more
Series by so notifying the Company in writing. The Holders of a majority in
principal amount of the Securities of any Series may remove the Trustee with
respect to that Series by so notifying the Trustee and the Company in writing.
The Company may remove the Trustee with respect to Securities of one or more
Series if:

            (a) the Trustee fails to comply with Section 7.10;

            (b) the Trustee is adjudged a bankrupt or an insolvent or an order
      for relief is entered with respect to the Trustee under any Bankruptcy
      Law;

            (c) a Custodian or public officer takes charge of the Trustee or its
      property; or

            (d) the Trustee becomes incapable of acting.

            If the Trustee resigns or is removed or if a vacancy exists in the
office of Trustee for any reason, the Company shall promptly appoint a successor
Trustee. Within one year after the successor Trustee takes office, the Holders
of a majority in principal amount of the then outstanding Securities may appoint
a successor Trustee to replace the successor Trustee appointed by the Company.

            If a successor Trustee with respect to the Securities of any one or
more Series does not take office within 60 days after the retiring Trustee
resigns or is removed, the retiring Trustee, the Company or the Holders of at
least 10% in principal amount of the Securities of the applicable Series may
petition any court of competent jurisdiction at the expense of the Company for
the appointment of a successor Trustee.

            If the Trustee with respect to the Securities of any one or more
Series fails to comply with Section 7.10, any Securityholder of the applicable
Series, who has been a Securityholder for at least six months, may petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.


                                       35
<PAGE>

            A successor Trustee shall deliver a written acceptance of its
appointment to the retiring Trustee and to the Company. Immediately after that,
the retiring Trustee shall transfer all property held by it as Trustee to the
successor Trustee subject to the lien provided for in Section 7.7, the
resignation or removal of the retiring Trustee shall become effective, and the
successor Trustee shall have all the rights, powers and duties of the Trustee
with respect to each Series of Securities for which it is acting as Trustee
under this Indenture. A successor Trustee shall mail a notice of its succession
to each Securityholder of each such Series and, if any Bearer Securities are
outstanding, publish such notice on one occasion in an Authorized Newspaper.
Notwithstanding replacement of the Trustee pursuant to this Section 7.8, the
Company's obligations under Section 7.7 hereof shall continue for the benefit of
the retiring trustee with respect to expenses and liabilities incurred by it
prior to such replacement.

      Section 7.9. Successor Trustee by Merger, etc.

            If the Trustee consolidates with, merges or converts into, or
transfers all or substantially all of its corporate trust business to, another
corporation, the successor corporation without any further act shall be the
successor Trustee.

      Section 7.10. Eligibility; Disqualification.

            This Indenture shall always have a Trustee who satisfies the
requirements of TIA Section 310(a)(1), (2) and (5). The Trustee shall always
have a combined capital and surplus of at least $50,000,000 as set forth in
its most recent published annual report of condition. The Trustee shall
comply with TIA Sections. 310(b).

      Section 7.11. Preferential Collection of Claims Against Company.

            The Trustee is subject to TIA Section 311(a), excluding any
creditor relationship listed in TIA Sections. 311(b). A Trustee who has
resigned or been removed shall be subject to TIA Sections. 311(a) to the
extent indicated.

                                 ARTICLE VIII.
                    LEGAL DEFEASANCE AND COVENANT DEFEASANCE

      Section 8.1. Option to Effect Legal Defeasance or Covenant Defeasance.

            The Company may, at the option of its Board of Directors evidenced
by a resolution set forth in an Officers' Certificate, at any time, elect to
have either Section 8.2 or 8.3 hereof be applied to all outstanding Securities
of a Series upon compliance with the conditions set forth below in this Article
Eight.

      Section 8.2. Legal Defeasance and Discharge.

            Upon the Company's exercise under Section 8.1 hereof of the option
applicable to this Section 8.2, each of the Company and the Guarantors, if any,
shall, subject to the satisfaction of the conditions set forth in Section 8.4
hereof, be deemed to have been discharged from its obligations with respect to
all outstanding Securites of such Series and related Subsidiary Guarantees on
the date the conditions set forth below are satisfied (hereinafter, "Legal


                                       36
<PAGE>

Defeasance"). For this purpose, Legal Defeasance means that the Company shall be
deemed to have paid and discharged the entire Indebtedness represented by the
outstanding Securities of such Series, which shall thereafter be deemed to be
"outstanding" only for the purposes of Section 8.5 hereof and the other Sections
of this Indenture referred to in (a) and (b) below, and to have satisfied all
its other obligations under such Securities and this Indenture as it relates to
such Securities (and the Trustee, on demand of and at the expense of the
Company, shall execute proper instruments acknowledging the same), except for
the following provisions which shall survive until otherwise terminated or
discharged hereunder: (a) the rights of Holders of outstanding Securities of
such Series to receive solely from the trust fund described in Section 8.4
hereof, and as more fully set forth in such section, payments in respect of the
principal of, premium, if any, and interest on such Securities when such
payments are due, (b) the Company's and Guarantors' obligations with respect to
such Securities under Article 2 hereof, (c) the rights, powers, trusts, duties
and immunities of the Trustee hereunder and the Company's and the Guarantors'
obligations in connection therewith and (d) this Article 8. Subject to
compliance with this Article 8, the Company may exercise its option under this
Section 8.2 notwithstanding the prior exercise of its option under Section 8.3
hereof.

      Section 8.3. Covenant Defeasance.

            Upon the Company's exercise under Section 8.1 hereof of the option
applicable to this Section 8.3, each of the Company and the Guarantors, if any,
shall, subject to the satisfaction of the conditions set forth in Section 8.4
hereof, be released from its obligations under the covenants specified pursuant
to Section 2.2 hereof and Article V hereof with respect to the outstanding
Securities of such Series and related Subsidiary Guarantees on and after the
date the conditions set forth below are satisfied (hereinafter, "Covenant
Defeasance"), and such Securities shall thereafter be deemed not "outstanding"
for the purposes of any direction, waiver, consent or declaration or act of
Holders (and the consequences of any thereof) in connection with such covenants,
but shall continue to be deemed "outstanding" for all other purposes hereunder
(it being understood that such Securities shall not be deemed outstanding for
accounting purposes). For this purpose, Covenant Defeasance means that, with
respect to the outstanding Securities of such Series, the Company may omit to
comply with and shall have no liability in respect of any term, condition or
limitation set forth in any such covenant, whether directly or indirectly, by
reason of any reference elsewhere herein to any such covenant or by reason of
any reference in any such covenant to any other provision herein or in any other
document and such omission to comply shall not constitute a Default or an Event
of Default under Section 6.1 hereof, but, except as specified above, the
remainder of this Indenture, such Securities and the related Subsidiary
Guarantees, if any, shall be unaffected thereby. In addition, upon the Company's
exercise under Section 8.1 hereof of the option applicable to this Section 8.3
hereof, subject to the satisfaction of the conditions set forth in Section 8.4
hereof, Sections 6.1(c) through 6.1(e) and 6.1(h) hereof (or any comparable
provisions set forth in a supplemental indenture) shall not constitute Events of
Default.

      Section 8.4. Conditions to Legal or Covenant Defeasance.

            The following shall be the conditions to the application of either
Section 8.2 or 8.3 hereof to the outstanding Securities of such Series:


                                       37
<PAGE>

            In order to exercise either Legal Defeasance or Covenant Defeasance:

            (a) the Company must irrevocably deposit with the Trustee, in trust,
      for the benefit of the Holders, cash in United States dollars,
      non-callable Government Securities, or a combination thereof, in such
      amounts as will be sufficient, in the opinion of a nationally recognized
      firm of independent public accountants, to pay the principal of, premium,
      if any, and interest on the outstanding Securities of such Series on the
      Stated Maturity or on the applicable redemption date, as the case may be,
      of such principal or installment of principal of, premium, if any, or
      interest on the outstanding Securities of such Series;

            (b) in the case of an election under Section 8.2 hereof, the Company
      shall have delivered to the Trustee an Opinion of Counsel in the United
      States (which counsel may be an employee of the Company or any Subsidiary
      of the Company) reasonably acceptable to the Trustee confirming that (A)
      the Company has received from, or there has been published by, the
      Internal Revenue Service a ruling or (B) since the date hereof, there has
      been a change in the applicable federal income tax law, in either case to
      the effect that, and based thereon such Opinion of Counsel shall confirm
      that, the Holders of the outstanding Securities of such Series will not
      recognize income, gain or loss for federal income tax purposes as a result
      of such Legal Defeasance and will be subject to federal income tax on the
      same amounts, in the same manner and at the same times as would have been
      the case if such Legal Defeasance had not occurred;

            (c) in the case of an election under Section 8.3 hereof, the Company
      shall have delivered to the Trustee an Opinion of Counsel in the United
      States (which counsel may be an employee of the Company or any Subsidiary
      of the Company) reasonably acceptable to the Trustee confirming that the
      Holders of the outstanding Securities of such Series will not recognize
      income, gain or loss for federal income tax purposes as a result of such
      Covenant Defeasance and will be subject to federal income tax on the same
      amounts, in the same manner and at the same times as would have been the
      case if such Covenant Defeasance had not occurred;

            (d) no Default or Event of Default shall have occurred and be
      continuing on the date of such deposit or, insofar as Sections 6.1(f) and
      6.1(g) hereof (or any comparable provisions set forth in a supplemental
      indenture) are concerned, at any time in the period ending on the 91st day
      after the date of deposit (or greater period of time in which any such
      deposit of trust funds may remain subject to Bankruptcy Law insofar as
      those apply to the deposit by the Company);

            (e) such Legal Defeasance or Covenant Defeasance shall not result in
      a breach or violation of, or constitute a default under, any material
      agreement or instrument (other than this Indenture) to which the Company
      or any of its Subsidiaries is a party or by which the Company or any of
      its Subsidiaries is bound;

            (f) the Company shall have delivered to the Trustee an Opinion of
      Counsel to the effect that after the 91st day following the deposit, the
      trust funds will not be subject


                                       38
<PAGE>

      to the effect of any applicable bankruptcy, insolvency, reorganization or
      similar laws affecting creditors' rights generally;

            (g) the Company shall have delivered to the Trustee an Officers'
      Certificate stating that the deposit was not made by the Company with the
      intent of preferring the Holders of such Securities over any other
      creditors of the Company with the intent of defeating, hindering, delaying
      or defrauding creditors of the Company or others; and

            (h) the Company shall have delivered to the Trustee an Officers'
      Certificate and an Opinion of Counsel, each stating that all conditions
      precedent provided for or relating to the Legal Defeasance or the Covenant
      Defeasance have been complied with.

      Section 8.5. Deposited Money and Government Securities to be Held in
                   Trust; Other Miscellaneous Provisions.

            Subject to Section 8.6 hereof, all money and non-callable Government
Securities (including the proceeds thereof) deposited with the Trustee (or other
qualifying trustee, collectively for purposes of this Section 8.5, the
"Trustee") pursuant to Section 8.4 hereof in respect of the outstanding
Securities of a Series subject to a Legal Defeasance or a Covenant Defeasance
shall be held in trust and applied by the Trustee, in accordance with the
provisions of such Notes and this Indenture, to the payment, either directly or
through any Paying Agent (including the Company acting as Paying Agent) as the
Trustee may determine, to the Holders of such Securities of all sums due and to
become due thereon in respect of principal, premium, if any, and interest, but
such money need not be segregated from other funds except to the extent required
by law.

            The Company and the Guarantors shall pay and indemnify the Trustee
against any tax, fee or other charge imposed on or assessed against the cash or
non-callable Government Securities deposited pursuant to Section 8.4 hereof or
the principal and interest received in respect thereof other than any such tax,
fee or other charge which by law is for the account of the Holders of the
outstanding Securities of a Series subject to a Legal Defeasance or a Covenant
Defeasance.

            Anything in this Article Eight to the contrary notwithstanding, the
Trustee shall deliver or pay to the Company from time to time upon the request
of the Company any money or non-callable Government Securities held by it as
provided in Section 8.4 hereof which, in the opinion of a nationally recognized
firm of independent public accountants expressed in a written certification
thereof delivered to the Trustee (which may be the opinion delivered under
Section 8.4(a) hereof), are in excess of the amount thereof that would then be
required to be deposited to effect an equivalent Legal Defeasance or Covenant
Defeasance.

      Section 8.6. Repayment to Company.

            Any money deposited with the Trustee or any Paying Agent, or then
held by the Company, in trust for the payment of the principal of, premium, if
any, or interest, if any, on any Securities of a Series subject to a Legal
Defeasance or a Covenant Defeasance and remaining unclaimed for two years after
such principal, and premium, if any, or interest, if any, have


                                       39
<PAGE>

become due and payable shall be paid to the Company on its request or (if then
held by the Company) shall be discharged from such trust; and the Holder of such
Security shall thereafter, as an unsecured general creditor, look only to the
Company for payment thereof, and all liability of the Trustee or such Paying
Agent with respect to such trust money, and all liability of the Company as
trustee thereof, shall thereupon cease; provided, however, that the Trustee or
such Paying Agent, before being required to make any such repayment, may at the
expense of the Company cause to be published once, in The New York Times and The
Wall Street Journal (national edition), notice that such money remains unclaimed
and that, after a date specified therein, which shall not be less than 30 days
from the date of such notification or publication, any unclaimed balance of such
money then remaining will be repaid to the Company.

      Section 8.7. Reinstatement.

            If the Trustee or Paying Agent is unable to apply any United States
dollars or non-callable Government Securities in accordance with Section 8.2 or
8.3 hereof, as the case may be, by reason of any order or judgment of any court
or governmental authority enjoining, restraining or otherwise prohibiting such
application, then the Company's obligations under this Indenture, the Securities
of such Series and the related Subsidiary Guarantees shall be revived and
reinstated as though no deposit had occurred pursuant to Section 8.2 or 8.3
hereof until such time as the Trustee or Paying Agent is permitted to apply all
such money in accordance with Section 8.2 or 8.3 hereof, as the case may be;
provided, however, that, if the Company make any payment of principal of,
premium, if any, or interest, if any, on any such Security following the
reinstatement of its obligations, the Company shall be subrogated to the rights
of the Holders of such Securities to receive such payment from the money held by
the Trustee or Paying Agent.

                                  ARTICLE IX.
                             AMENDMENTS AND WAIVERS

      Section 9.1. Without Consent of Holders.

            The Company, the Guarantors and the Trustee may amend or supplement
this Indenture or the Securities of one or more Series without the consent of
any Securityholder:

            (a) to cure any ambiguity, defect or inconsistency;

            (b) to comply with Article V;

            (c) to provide for uncertificated Securities in addition to or in
      place of certificated Securities;

            (d) to make any change that does not materially adversely affect the
      rights of any Securityholder;

            (e) to provide for the issuance of and establish the form and terms
      and conditions of Securities of any Series as permitted by this Indenture;


                                       40
<PAGE>

            (f) to evidence and provide for the acceptance of appointment
      hereunder by a successor Trustee with respect to the Securities of one or
      more Series and to add to or change any of the provisions of this
      Indenture as shall be necessary to provide for or facilitate the
      administration of the trusts hereunder by more than one Trustee; or

            (g) to comply with requirements of the SEC in order to effect or
      maintain the qualification of this Indenture under the TIA.

      Section 9.2. With Consent of Holders.

            The Company, the Guarantors and the Trustee may enter into a
supplemental indenture with the written consent of the Holders of at least a
majority in principal amount of the outstanding Securities of each Series
affected by such supplemental indenture (including consents obtained in
connection with a tender offer or exchange offer for the Securities of such
Series), for the purpose of adding any provisions to or changing in any manner
or eliminating any of the provisions of this Indenture or of any supplemental
indenture or of modifying in any manner the rights of the Securityholders of
each such Series. Except as provided in Section 6.13, the Holders of at least a
majority in principal amount of the outstanding Securities of each Series
affected by such waiver by notice to the Trustee (including consents obtained in
connection with a tender offer or exchange offer for the Securities of such
Series) may waive compliance by the Company with any provision of this Indenture
or the Securities with respect to such Series.

            It shall not be necessary for the consent of the Holders of
Securities under this Section 9.2 to approve the particular form of any proposed
supplemental indenture or waiver, but it shall be sufficient if such consent
approves the substance thereof. After a supplemental indenture or waiver under
this section becomes effective, the Company shall mail to the Holders of
Securities affected thereby and, if any Bearer Securities affected thereby are
outstanding, publish on one occasion in an Authorized Newspaper, a notice
briefly describing the supplemental indenture or waiver. Any failure by the
Company to mail or publish such notice, or any defect therein, shall not,
however, in any way impair or affect the validity of any such supplemental
indenture or waiver.

      Section 9.3. Limitations.

            Without the consent of each Securityholder affected, an amendment or
waiver may not:

            (a) reduce the principal amount of Securities whose Holders must
      consent to an amendment, supplement or waiver;

            (b) reduce the rate of or change the time for payment of interest on
      any Security;

            (c) reduce the principal of or change the Stated Maturity of any
      Security or alter any of the provisions with respect to the redemption of
      the Security in a manner adverse to the Holders of the Security;


                                       41
<PAGE>

            (d) waive a Default or Event of Default in the payment of the
      principal of or premium, if any, or interest, if any, on any Security
      (except a rescission of acceleration of the Securities of any Series by
      the Holders of at least a majority in principal amount of the outstanding
      Securities of such Series and a waiver of the payment default that
      resulted from such acceleration);

            (e) make the principal of or interest, if any, on any Security
      payable in any currency other than that stated in the Security;

            (f) make any change in the provisions of this Indenture relating to
      waivers of past Defaults or the rights of Holders of the Securities of any
      Series to receive payments of principal of or premium, if any, or interest
      on such Security;

            (g) waive a redemption payment with respect to any Security or
      change any of the provisions with respect to the redemption of any
      Securities; or

            (h) make any change in the foregoing amendment and waiver
      provisions.

      Section 9.4. Compliance with Trust Indenture Act.

            Every amendment to this Indenture or the Securities of one or more
Series shall be set forth in a supplemental indenture hereto that complies with
the TIA as then in effect.

      Section 9.5. Revocation and Effect of Consents.

            Until an amendment or waiver becomes effective, a consent to it by a
Holder of a Security is a continuing consent by the Holder and every subsequent
Holder of a Security or portion of a Security that evidences the same debt as
the consenting Holder's Security, even if notation of the consent is not made on
any Security. However, any such Holder or subsequent Holder may revoke the
consent as to his Security or portion of a Security if the Trustee receives the
notice of revocation before the date the amendment or waiver becomes effective.

            Any amendment or waiver once effective shall bind every
Securityholder of each Series affected by such amendment or waiver unless it is
of the type described in any of clauses (a) through (g) of Section 9.3. In that
case, the amendment or waiver shall bind each Holder of a Security who has
consented to it and every subsequent Holder of a Security or portion of a
Security that evidences the same debt as the consenting Holder's Security.

      Section 9.6. Notation on or Exchange of Securities.

            The Trustee may place an appropriate notation about an amendment or
waiver on any Security of any Series thereafter authenticated. The Company in
exchange for Securities of that Series may issue and the Trustee shall
authenticate upon request new Securities of that Series that reflect the
amendment or waiver.


                                       42
<PAGE>

      Section 9.7. Trustee to Sign Amendments; Trustee Protected.

            The Trustee shall sign any amended or supplemental Indenture
authorized pursuant to this Article IX if the amendment or supplement does not
adversely affect the rights, duties, liabilities or immunities of the Trustee.
In executing, or accepting the additional trusts created by, any supplemental
indenture permitted by this Article or the modifications thereby of the trusts
created by this Indenture, the Trustee shall be entitled to receive, and
(subject to Section 7.1) shall be fully protected in relying upon, an Opinion of
Counsel and Officers' Certificate stating that the execution of such
supplemental indenture is authorized or permitted by this Indenture. The Trustee
shall sign all supplemental indentures, except that the Trustee need not sign
any supplemental indenture that adversely affects its rights.

                                   ARTICLE X.
                                  MISCELLANEOUS

      Section 10.1. Trust Indenture Act Controls.

            If any provision of this Indenture limits, qualifies, or conflicts
with another provision which is required or deemed to be included in this
Indenture by the TIA, such required or deemed provision shall control.

      Section 10.2. Notices.

            Any notice or communication by the Company, any Guarantor or the
Trustee to the others is duly given if in writing and delivered in Person or
mailed by first class mail (registered or certified, return receipt requested),
telecopier or overnight air courier guaranteeing next day delivery, to the
others' address:

         If to the Company or any Guarantor:

                           Iron Mountain Incorporated
                           745 Atlantic Avenue
                           Boston, MA 02111
                           Attention: Chief Financial Officer
                           Telecopier No.: (617) 350-7881

         With a copy to:

                           Sullivan & Worcester LLP
                           One Post Office Square
                           Boston, MA  02109
                           Telecopier No.: (617) 338-2880
                           Attention: William J. Curry, Esq.


                                       43
<PAGE>

         If to the Trustee:

                           The Bank of New York
                           101 Barclay Street, Floor 21W
                           New York, New York 10286
                           Telecopier No.: (212) 815-5915
                           Attention: Corporate Trust Trustee Administration

            The Company, any Guarantor or the Trustee, by notice to the others
may designate additional or different addresses for subsequent notices or
communications.

            All notices and communications (other than those sent to
Securityholders) must reference the Securities and this Indenture and shall be
deemed to have been duly given: at the time delivered by hand, if personally
delivered; five Business Days after being deposited in the mail, postage
prepaid, if mailed; when receipt acknowledged, if telecopied; and the next
Business Day after timely delivery to the courier, if sent by overnight air
courier guaranteeing next day delivery.

            Any notice or communication to a Securityholder shall be mailed
by first class mail, or by overnight air courier guaranteeing next day
delivery to its address shown on the register kept by the Registrar. Any
notice or communication shall also be so mailed to any Person described in
TIA Section 313(c), to the extent required by the TIA. Failure to mail a
notice or communication to a Securityholder or any defect in it shall not
affect its sufficiency with respect to other Securityholders.

            If a notice or communication is mailed in the manner provided above
within the time prescribed, it is duly given, whether or not the addressee
receives it.

            If the Company or any Guarantor mails a notice or communication to
Securityholders, it shall mail a copy to the Trustee and each Agent at the same
time.

      Section 10.3. Communication by Holders with Other Holders.

            Securityholders of any Series may communicate pursuant to TIA
Section 312(b) with other Securityholders of that Series or any other Series
with respect to their rights under this Indenture or the Securities of that
Series or all Series. The Company, the Guarantors, the Trustee, the Registrar
and anyone else shall have the protection of TIA Sections. 312(c).

      Section 10.4. Certificate and Opinion as to Conditions Precedent.

            Upon any request or application by the Company or any Guarantor to
the Trustee to take any action under this Indenture, the Company or such
Guarantor shall furnish to the Trustee:

            (a) an Officers' Certificate stating that, in the opinion of the
      signers, all conditions precedent, if any, provided for in this Indenture
      relating to the proposed action have been complied with; and


                                       44
<PAGE>

            (b) an Opinion of Counsel stating that, in the opinion of such
      counsel, all such conditions precedent have been complied with.

      Section 10.5. Statements Required in Certificate or Opinion.

            Each certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (other than a
certificate provided pursuant to TIA Section 314(a)(4)) shall comply with the
provisions of TIA Sections. 314(e) and shall include:

            (a) a statement that the Person making such certificate or opinion
      has read such covenant or condition;

            (b) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based;

            (c) a statement that, in the opinion of such Person, he has made
      such examination or investigation as is necessary to enable him to express
      an informed opinion as to whether or not such covenant or condition has
      been complied with; and

            (d) a statement as to whether or not, in the opinion of such Person,
      such condition or covenant has been complied with.

      Section 10.6. Rules by Trustee and Agents.

            The Trustee may make reasonable rules for action by or a meeting of
Securityholders of one or more Series. Any Agent may make reasonable rules and
set reasonable requirements for its functions.

      Section 10.7. Legal Holidays.

            Unless otherwise provided by Board Resolution, Officers' Certificate
or supplemental indenture for a particular Series, a "Legal Holiday" is any day
that is not a Business Day. If a payment date is a Legal Holiday at a place of
payment, payment may be made at that place on the next succeeding day that is
not a Legal Holiday, and no interest shall accrue for the intervening period.

      Section 10.8. No Personal Liability of Directors, Officers, Employees and
Stockholders.

            No past, present or future director, officer, employee, incorporator
or stockholder of the Company or any Guarantor, as such, shall have any
liability for any obligations of the Company or any Guarantor under the
Securities of any Series, the Subsidiary Guarantees, this Indenture or for any
claim based on, in respect of, or by reason of, such obligations or their
creation. Each Holder of Securities of any Series, by accepting a Security and
the related Subsidiary Guarantees waives and releases all such liability. The
waiver and release are part of the consideration for issuance of the Series of
Securities and the Subsidiary Guarantees.


                                       45
<PAGE>

      Section 10.9. Counterparts.

            This Indenture may be executed in any number of counterparts and by
the parties hereto in separate counterparts, each of which when so executed
shall be deemed to be an original and all of which taken together shall
constitute one and the same agreement.

      Section 10.10. Governing Laws.

            THIS INDENTURE AND THE SECURITIES SHALL BE GOVERNED BY THE LAWS OF
THE STATE OF NEW YORK APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN SUCH
STATE, WITHOUT REGARD TO THE CONFLICT OF LAWS PROVISIONS THEREOF.

      Section 10.11. No Adverse Interpretation of Other Agreements.

            This Indenture may not be used to interpret another indenture, loan
or debt agreement of the Company or a Subsidiary. Any such indenture, loan or
debt agreement may not be used to interpret this Indenture.

      Section 10.12. Successors.

            All agreements of the Company and the Guarantors in this Indenture
and the Securities and the Subsidiary Guarantees shall bind their respective
successors. All agreements of the Trustee in this Indenture shall bind its
successors.

      Section 10.13. Severability.

            In case any provision in this Indenture, the Securities or the
Subsidiary Guarantees, if any, shall be invalid, illegal or unenforceable, the
validity, legality and enforceability of the remaining provisions shall not in
any way be affected or impaired thereby.

      Section 10.14. Table of Contents, Headings, Etc.

            The Table of Contents, Cross Reference Table, and headings of the
Articles and Sections of this Indenture have been inserted for convenience of
reference only, are not to be considered a part hereof, and shall in no way
modify or restrict any of the terms or provisions hereof.

      Section 10.15. Securities in a Foreign Currency or in ECU.

            Unless otherwise specified in a Board Resolution, a supplemental
indenture hereto or an Officers' Certificate delivered pursuant to Section 2.2
of this Indenture with respect to a particular Series of Securities, whenever
for purposes of this Indenture any action may be taken by the Holders of a
specified percentage in aggregate principal amount of Securities of all Series
or all Series affected by a particular action at the time outstanding and, at
such time, there are outstanding Securities of any Series which are denominated
in a coin or currency other than Dollars (including ECUs), then the principal
amount of Securities of such Series which shall be deemed to be outstanding for
the purpose of taking such action shall be that amount of Dollars


                                       46
<PAGE>

that could be obtained for such amount at the Market Exchange Rate at such time.
For purposes of this Section 10.15, "Market Exchange Rate" shall mean the noon
Dollar buying rate in New York City for cable transfers of that currency as
published by the Federal Reserve Bank of New York; provided, however, in the
case of ECUs, Market Exchange Rate shall mean the rate of exchange determined by
the Commission of the European Union (or any successor thereto) as published in
the Official Journal of the European Union (such publication or any successor
publication, the "Journal"). If such Market Exchange Rate is not available for
any reason with respect to such currency, the Trustee shall use, in its sole
discretion and without liability on its part, such quotation of the Federal
Reserve Bank of New York or, in the case of ECUs, the rate of exchange as
published in the Journal, as of the most recent available date, or quotations
or, in the case of ECUs, rates of exchange from one or more major banks in The
City of New York or in the country of issue of the currency in question or, in
the case of ECUs, in Luxembourg or such other quotations or, in the case of
ECUs, rates of exchange as the Trustee, upon consultation with the Company,
shall deem appropriate. The provisions of this paragraph shall apply in
determining the equivalent principal amount in respect of Securities of a Series
denominated in currency other than Dollars in connection with any action taken
by Holders of Securities pursuant to the terms of this Indenture.

            All decisions and determinations of the Trustee regarding the Market
Exchange Rate or any alternative determination provided for in the preceding
paragraph shall be in its sole discretion and shall, in the absence of manifest
error, be conclusive to the extent permitted by law for all purposes and
irrevocably binding upon the Company and all Holders.

      Section 10.16. Judgment Currency.

            The Company agrees, to the fullest extent that it may effectively do
so under applicable law, that (a) if for the purpose of obtaining judgment in
any court it is necessary to convert the sum due in respect of the principal of
or interest or other amount on the Securities of any Series (the "Required
Currency") into a currency in which a judgment will be rendered (the "Judgment
Currency"), the rate of exchange used shall be the rate at which in accordance
with normal banking procedures the Trustee could purchase in The City of New
York the Required Currency with the Judgment Currency on the day on which final
unappealable judgment is entered, unless such day is not a New York Banking Day,
then, the rate of exchange used shall be the rate at which in accordance with
normal banking procedures the Trustee could purchase in The City of New York the
Required Currency with the Judgment Currency on the New York Banking Day
preceding the day on which final unappealable judgment is entered and (b) its
obligations under this Indenture to make payments in the Required Currency (i)
shall not be discharged or satisfied by any tender, any recovery pursuant to any
judgment (whether or not entered in accordance with subsection (a)), in any
currency other than the Required Currency, except to the extent that such tender
or recovery shall result in the actual receipt, by the payee, of the full amount
of the Required Currency expressed to be payable in respect of such payments,
(ii) shall be enforceable as an alternative or additional cause of action for
the purpose of recovering in the Required Currency the amount, if any, by which
such actual receipt shall fall short of the full amount of the Required Currency
so expressed to be payable, and (iii) shall not be affected by judgment being
obtained for any other sum due under this Indenture. For purposes of the
foregoing, "New York Banking Day" means any day except a Saturday, Sunday


                                       47
<PAGE>

or a legal holiday in The City of New York on which banking institutions are
authorized or required by law, regulation or executive order to close.

                                  ARTICLE XI.
                                  SINKING FUNDS

      Section 11.1. Applicability of Article.

            The provisions of this Article shall be applicable to any sinking
fund for the retirement of the Securities of a Series, except as otherwise
permitted or required by any form of Security of such Series issued pursuant to
this Indenture.

            The minimum amount of any sinking fund payment provided for by the
terms of the Securities of any Series is herein referred to as a "mandatory
sinking fund payment" and any other amount provided for by the terms of
Securities of such Series is herein referred to as an "optional sinking fund
payment." If provided for by the terms of Securities of any Series, the cash
amount of any sinking fund payment may be subject to reduction as provided in
Section 11.2. Each sinking fund payment shall be applied to the redemption of
Securities of any Series as provided for by the terms of the Securities of such
Series.

      Section 11.2. Satisfaction of Sinking Fund Payments with Securities.

            The Company may, in satisfaction of all or any part of any sinking
fund payment with respect to the Securities of any Series to be made pursuant to
the terms of such Securities (1) deliver outstanding Securities of such Series
to which such sinking fund payment is applicable (other than any of such
Securities previously called for mandatory sinking fund redemption) and (2)
apply as credit Securities of such Series to which such sinking fund payment is
applicable and which have been redeemed either at the election of the Company
pursuant to the terms of such Series of Securities (except pursuant to any
mandatory sinking fund) or through the application of permitted optional sinking
fund payments or other optional redemptions pursuant to the terms of such
Securities, provided that such Securities have not been previously so credited.
Such Securities shall be received by the Trustee, together with an Officers'
Certificate with respect thereto, not later than 15 days prior to the date on
which the Trustee begins the process of selecting Securities for redemption, and
shall be credited for such purpose by the Trustee at the price specified in such
Securities for redemption through operation of the sinking fund and the amount
of such sinking fund payment shall be reduced accordingly. If as a result of the
delivery or credit of Securities in lieu of cash payments pursuant to this
Section 11.2, the principal amount of Securities of such Series to be redeemed
in order to exhaust the aforesaid cash payment shall be less than $100,000, the
Trustee need not call Securities of such Series for redemption, except upon
receipt of a Company Order that such action be taken, and such cash payment
shall be held by the Trustee or a Paying Agent and applied to the next
succeeding sinking fund payment, provided, however, that the Trustee or such
Paying Agent shall from time to time upon receipt of a Company Order pay over
and deliver to the Company any cash payment so being held by the Trustee or such
Paying Agent upon delivery by the Company to the Trustee of Securities of that
Series purchased by the Company having an unpaid principal amount equal to the
cash payment required to be released to the Company.


                                       48
<PAGE>

      Section 11.3. Redemption of Securities for Sinking Fund.

            Not less than 45 days (unless otherwise indicated in the Board
Resolution, supplemental indenture hereto or Officers' Certificate in respect of
a particular Series of Securities) prior to each sinking fund payment date for
any Series of Securities, the Company will deliver to the Trustee an Officers'
Certificate specifying the amount of the next ensuing mandatory sinking fund
payment for that Series pursuant to the terms of that Series, the portion
thereof, if any, which is to be satisfied by payment of cash and the portion
thereof, if any, which is to be satisfied by delivering and crediting of
Securities of that Series pursuant to Section 11.2, and the optional amount, if
any, to be added in cash to the next ensuing mandatory sinking fund payment, and
the Company shall thereupon be obligated to pay the amount therein specified.
Not less than 30 days (unless otherwise indicated in the Board Resolution,
Officers' Certificate or supplemental indenture in respect of a particular
Series of Securities) before each such sinking fund payment date the Trustee
shall select the Securities to be redeemed upon such sinking fund payment date
in the manner specified in Section 3.2 and cause notice of the redemption
thereof to be given in the name of and at the expense of the Company in the
manner provided in Section 3.3. Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Sections 3.4, 3.5 and 3.6.

                                  ARTICLE XII.
                              SUBSIDIARY GUARANTEES

      Section 12.1. Subsidiary Guarantee.

            Each Subsidiary that is a signatory hereto and each Subsidiary of
the Company that in accordance with the terms of any Securities of a Series
issued hereunder pursuant to any supplement indenture relating to such
Securities is required to become party to this Indenture as a guarantor (each, a
"Guarantor"), hereby jointly and severally unconditionally guarantees to each
Securityholder of a Security of a Series that is to be guaranteed and that has
been authenticated and delivered by the Trustee irrespective of the validity or
enforceability of this Indenture, the Securities or the obligations of the
Company under this Indenture or the Securities, that: (i) the principal of and
interest on the Securities will be paid in full when due, whether at the
maturity or interest payment or mandatory redemption date, by acceleration, call
for redemption or otherwise, and interest on the overdue principal of and
interest, if any, on the Securities and all other obligations of the Company to
the Securityholders or the Trustee under this Indenture or the Securities will
be promptly paid in full or performed, all in accordance with the terms of this
Indenture and the Securities; and (ii) in case of any extension of time of
payment or renewal of any Securities or any of such other obligations, they will
be paid in full when due or performed in accordance with the terms of the
extension or renewal, whether at maturity, by acceleration or otherwise. Failing
payment when due of any amount so guaranteed for whatever reason, each Guarantor
will be obligated to pay the same whether or not such failure to pay has become
an Event of Default which could cause acceleration pursuant to Section 6.2
hereof. Each Guarantor agrees that this is a guarantee of payment not a
guarantee of collection.

            Each Guarantor hereby agrees that its obligations with regard to
this Subsidiary Guarantee shall be joint and several and unconditional,
irrespective of the validity or


                                       49
<PAGE>

enforceability of the Securities or the obligations of the Company under this
Indenture, the absence of any action to enforce the same, the recovery of any
judgment against the Company or any other obligor with respect to this
Indenture, the Securities or the obligations of the Company under this Indenture
or the Securities, any action to enforce the same or any other circumstances
(other than complete performance) which might otherwise constitute a legal or
equitable discharge or defense of a Guarantor. Each Guarantor further, to the
extent permitted by law, waives and relinquishes all claims, rights and remedies
accorded by applicable law to guarantors and agrees not to assert or take
advantage of any such claims, rights or remedies, including but not limited to:
(a) any right to require the Trustee, the Securityholders or the Company (each,
a "Benefited Party") to proceed against the Company or any other Person or to
proceed against or exhaust any security held by a Benefited Party at any time or
to pursue any other remedy in any Benefited Party's power before proceeding
against such Guarantor; (b) the defense of the statute of limitations in any
action hereunder or in any action for the collection of any Indebtedness or the
performance of any obligation hereby guaranteed; (c) any defense that may arise
by reason of the incapacity, lack of authority, death or disability of any other
Person or the failure of a Benefited Party to file or enforce a claim against
the estate (in administration, bankruptcy or any other proceeding) of any other
Person; (d) demand, protest and notice of any kind including but not limited to
notice of the existence, creation or incurring of any new or additional
Indebtedness or obligation or of any action or non-action on the part of such
Guarantor, the Company, any Benefited Party, any creditor of such Guarantor, the
Company or on the part of any other Person whomsoever in connection with any
Indebtedness or obligations hereby guaranteed; (e) any defense based upon an
election of remedies by a Benefited Party, including but not limited to an
election to proceed against such Guarantor for reimbursement; (f) any defense
based upon any statute or rule of law which provides that the obligation of a
surety must be neither larger in amount nor in other respects more burdensome
than that of the principal; (g) any defense arising because of a Benefited
Party's election, in any proceeding instituted under Bankruptcy Law, of the
application of 11 U.S.C. Section 1111(b)(2); or (h) any defense based on any
borrowing or grant of a security interest under 11 U.S.C. Section 364. Each
Guarantor hereby covenants that its Subsidiary Guarantee will not be discharged
except by complete performance of the obligations contained in its Subsidiary
Guarantee and this Indenture.

            If any Securityholder or the Trustee is required by any court or
otherwise to return to either the Company or any Guarantor, or any Custodian
acting in relation to either the Company or such Guarantor, any amount paid by
the Company or such Guarantor to the Trustee or such Securityholder, the
applicable Subsidiary Guarantees, to the extent theretofore discharged, shall be
reinstated and be in full force and effect. Each Guarantor agrees that it will
not be entitled to any right of subrogation in relation to the Securityholders
in respect of any obligations guaranteed hereby until payment in full of all
obligations guaranteed hereby.

            Each Guarantor further agrees that, as between such Guarantor, on
the one hand, and the Securityholders and the Trustee, on the other hand, (i)
the maturity of the obligations guaranteed hereby may be accelerated as provided
in Section 6.2 hereof for the purposes of this Subsidiary Guarantee,
notwithstanding any stay, injunction or other prohibition preventing such
acceleration as to the Company or any other obligor on the Securities of the
obligations guaranteed hereby, and (ii) in the event of any declaration of
acceleration of those obligations as


                                       50
<PAGE>

provided in Section 6.2 hereof, those obligations (whether or not due and
payable) will forthwith become due and payable by such Guarantor for the purpose
of this Subsidiary Guarantee.

      Section 12.2. Limitation of Guarantor's Liability.

            Each Guarantor and, by its acceptance hereof, the Trustee and each
Securityholder hereby confirm that it is its intention that the Subsidiary
Guarantee of such Guarantor not constitute a fraudulent transfer or conveyance
for purposes of the Bankruptcy Law, the Uniform Fraudulent Conveyance Act, the
Uniform Fraudulent Transfer Act or any similar federal or state law to the
extent applicable to any Subsidiary Guarantee. To effectuate the foregoing
intention, each such Person hereby irrevocably agrees that the obligation of
such Guarantor under its Subsidiary Guarantee under this Article 12 shall be
limited to the maximum amount as will, after giving effect to such maximum
amount and all other (contingent or other) liabilities of such Guarantor that
are relevant under such laws, and after giving effect to any collections from,
rights to receive contribution from or payments made by or on behalf of any
other Guarantor in respect of the obligations of such other Guarantor under this
Article 12, result in the obligations of such Guarantor in respect of such
maximum amount not constituting a fraudulent transfer or conveyance under said
laws. The Trustee and each Securityholder by accepting the benefits hereof,
confirms its intention that, in the event of a bankruptcy, reorganization or
other similar proceeding of the Company or any Guarantor in which concurrent
claims are made upon such Guarantor hereunder, to the extent such claims will
not be fully satisfied, each such claimant with a valid claim against the
Company shall be entitled to a ratable share of all payments by such Guarantor
in respect of such concurrent claims. For all purposes of this Section 12.2,
Senior Debt shall be deemed to have been incurred prior to the incurrence of the
obligations in respect of the Subsidiary Guarantees.

                                 ARTICLE XIII.
                                  SUBORDINATION

      Section 13.1. Agreement to Subordinate.

            The Company, the Trustee and each Securityholder by accepting a
Security agrees, that the indebtedness and obligations evidenced by the Security
(a) rank pari passu with the Company's Obligations relating to the Existing
Senior Subordinated Securities and (b) are subordinated in right of payment, to
the extent and in the manner provided in this Article, to the prior payment in
full, in cash, of all Obligations with respect to Senior Debt of the Company
(whether outstanding on the date hereof or hereafter created, incurred, assumed
or guaranteed), and that the subordination is for the benefit of the holders of
Senior Debt of the Company.

      Section 13.2. Liquidation; Dissolution; Bankruptcy.

            Upon any payment or distribution to creditors of the Company in a
liquidation or dissolution of the Company or in a bankruptcy, reorganization,
insolvency, receivership or similar proceeding relating to the Company or its
property, in an assignment for the benefit of creditors or any marshaling of the
Company's assets and liabilities:


                                       51
<PAGE>

            (1) holders of Senior Debt of the Company shall be entitled to
      receive payment in full in cash of all Obligations due in respect of such
      Senior Debt of the Company (including interest after the commencement of
      any such proceeding at the rate specified in the applicable Senior Debt of
      the Company, whether or not allowed as a claim in such proceeding) before
      Securityholders shall be entitled to receive any payment or distribution
      from the Company with respect to the Securities; and

            (2) until all Obligations with respect to Senior Debt of the Company
      (as provided in subsection (1) above) are paid in full in cash, any
      payment or distribution to which the Trustee or any Securityholder would
      be entitled but for this Article shall be made to holders of Senior Debt
      of the Company, as their interests may appear.

      Section 13.3. Default on Designated Senior Debt.

            The Company may not make any payment or distribution upon or in
respect of the Securities, including, without limitation, by way of set-off or
otherwise, or redeem (or make a deposit in redemption of), defease or acquire
any of the Securities, for cash, properties or securities if:

            (i) a default in the payment of any principal, premium, if any, or
      interest or other Obligations (a "Payment Default") with respect to Senior
      Debt of the Company occurs and is continuing; or

            (ii) a default (other than a Payment Default) or any event that,
      after notice or passage of time would become a default (a "Non-Monetary
      Default"), on Senior Debt of the Company occurs and is continuing that
      then permits holders of the Senior Debt of the Company to accelerate its
      maturity and the Trustee receives a notice of the default (a "Payment
      Blockage Notice") from a Person who may give it pursuant to Section 13.11
      hereof. Any number of such Payment Blockage Notices may be given,
      provided, however, that (i) not more than one Payment Blockage Notice may
      be commenced during any period of 360 consecutive days and (ii) any
      Non-Monetary Default that existed or was continuing on the date of
      delivery of any such notice to the Trustee (to the extent the holder of
      Designated Senior Debt, or such trustee or agent, giving such Payment
      Blockage Notice had knowledge of the same) shall not be the basis for a
      subsequent Payment Blockage Notice, unless such default has been cured or
      waived for a period of not less than 90 days.

            The Company may and shall resume payments on and distributions in
respect of the Securities and all Obligations with respect thereto, and may
acquire such Securities or Obligations upon the earlier of:

            (1) in the case of a payment default, the date upon which such
      default is cured or waived, or


                                       52
<PAGE>

            (2) in the case of a Non-Monetary Default, on the earlier of the
      date on which such Non-Monetary Default is cured or waived or 179 days
      after the date on which the applicable Payment Blockage Notice is
      received, if the maturity of such Senior Debt of the Company has not been
      accelerated,

if this Article 13 otherwise permits the payment, distribution or acquisition at
the time thereof.

      Section 13.4. Acceleration of Securities.

            If payment of the Securities is accelerated because of an Event of
Default, the Company shall promptly notify Representatives of the holders of
Senior Debt of the Company of the acceleration.

      Section 13.5. When Distribution Must be Paid Over.

            In the event that the Trustee or any Securityholder receives from
the Company any payment of any Obligations with respect to the Securities at a
time when the Trustee or such Securityholder, as applicable, has actual
knowledge that such payment is prohibited by Section 13.2 or 13.3 hereof, such
payment shall be held by the Trustee or such Securityholder in trust for the
benefit of, and shall be paid forthwith over and delivered upon written request
to, the holders of Senior Debt of the Company, as their interests may appear, or
their Representative under the indenture or other agreement (if any) pursuant to
which Senior Debt of the Company may have been issued, as their respective
interests may appear, for application to the payment of all Obligations with
respect to Senior Debt of the Company remaining unpaid to the extent necessary
to pay such Obligations in full in accordance with their terms, after giving
effect to any concurrent payment or distribution to or for the holders of Senior
Debt of the Company.

            With respect to the holders of Senior Debt of the Company, the
Trustee undertakes to perform only such obligations on the part of the Trustee
as are specifically set forth in this Article 13, and no implied covenants or
obligations with respect to the holders of Senior Debt of the Company shall be
read into this Indenture against the Trustee. The Trustee shall not be deemed to
owe any fiduciary duty to the holders of Senior Debt of the Company, and shall
not be liable to any such holders if the Trustee shall pay over or distribute to
or on behalf of Securityholders or the Company or any other Person money or
assets to which any holders of Senior Debt of the Company shall be entitled by
virtue of this Article 13, except if such payment is made as a result of the
willful misconduct or gross negligence of the Trustee.

      Section 13.6. Notice By Company.

            The Company shall promptly notify the Trustee and the Paying Agent
of any facts known to the Company that would cause a payment of any Obligations
with respect to the Securities to violate this Article, but failure to give such
notice shall not affect the subordination of the Securities to the Senior Debt
of the Company as provided in this Article.


                                       53
<PAGE>

      Section 13.7. Subrogation.

            After all Obligations with respect to Senior Debt of the Company are
paid in full, in cash, and until the Securities are paid in full,
Securityholders shall be subrogated (equally and ratably with all other
Indebtedness pari passu with the Securities) to the rights of holders of Senior
Debt of the Company to receive distributions applicable to Senior Debt of the
Company to the extent that distributions otherwise payable to the
Securityholders have been applied to the payment of Senior Debt of the Company.
A distribution made under this Article to holders of Senior Debt of the Company
that otherwise would have been made to Securityholders is not, as between the
Company and Securityholders, a payment by the Company on the Securities.

      Section 13.8. Relative Rights.

            This Article defines the relative rights of Securityholders and
holders of Senior Debt of the Company. Nothing in this Indenture shall:

                  (1) impair, as between the Company and Securityholders, the
            obligation of the Company, which is absolute and unconditional, to
            pay principal of and interest on the Securities in accordance with
            their terms;

                  (2) affect the relative rights of Securityholders and
            creditors of the Company other than their rights in relation to
            holders of Senior Debt of the Company; or

                  (3) prevent the Trustee or any Securityholder from exercising
            its available remedies upon a Default or Event of Default, subject
            to the rights of holders and owners of Senior Debt of the Company to
            receive distributions and payments otherwise payable to
            Securityholders.

            If the Company fails because of this Article 13 to pay principal of,
premium or interest on a Security on the due date, the failure is still a
Default or Event of Default.

      Section 13.9. Subordination May Not Be Impaired by Company.

            No right of any holder of Senior Debt of the Company to enforce the
subordination of the Indebtedness evidenced by the Securities shall be impaired
by any act or failure to act by the Company or any Securityholder or by the
failure of the Company or any Securityholder to comply with this Indenture.

      Section 13.10. Distribution or Notice to Representative.

            Whenever a distribution is to be made or a notice given to holders
of Senior Debt of the Company, the distribution may be made and the notice given
to their Representative.

            Upon any payment or distribution of assets of the Company referred
to in this Article 13, the Trustee and the Securityholders shall be entitled to
rely upon any order or decree made by any court of competent jurisdiction or
upon any certificate of such Representative or of the liquidating trustee or
agent or other Person making any distribution to the Trustee or to the


                                       54
<PAGE>

Securityholders for the purpose of ascertaining the Persons entitled to
participate in such distribution, the holders of the Senior Debt of the Company
and other Indebtedness of the Company, the amount or amounts thereof or payable
thereon, the amount or amounts paid or distributed thereon and all other facts
pertinent thereto or to this Article 13.

      Section 13.11. Rights of Trustee and Paying Agent.

            Notwithstanding the provisions of this Article 13 or any other
provision of this Indenture, the Trustee shall not be charged with knowledge of
the existence of any facts that would prohibit the making of any payment or
distribution by the Trustee, and the Trustee and the Paying Agent may continue
to make payments on the Securities, unless the Trustee shall have received at
its Corporate Trust Office at least one Business Day prior to the date of such
payment a Payment Blockage Notice. Only the holders or the Representative of
holders of Designated Senior Debt of the Company may give a Payment Blockage
Notice. Nothing in this Article 13 shall impair the claims of, or payments to,
the Trustee under or pursuant to Section 7.7 hereof.

            The Trustee in its individual or any other capacity may hold Senior
Debt of the Company with the same rights it would have if it were not Trustee.
Any Agent may do the same with like rights.

      Section 13.12. Authorization to Effect Subordination.

            Each Securityholder of a Security by the Securityholder's acceptance
thereof authorizes and directs the Trustee on the Securityholder's behalf to
take such action as may be necessary or appropriate to effectuate the
subordination as provided in this Article 13, and appoints the Trustee to act as
the Securityholder's attorney-in-fact for any and all such purposes. If the
Trustee does not file a proper proof of claim or proof of debt in the form
required in any proceeding referred to in Section 6.4 hereof at least 30 days
before the expiration of the time to file such claim, the Representatives of the
Senior Debt of the Company are hereby authorized to file an appropriate claim
for and on behalf of the Securityholders of the Securities.

      Section 13.13. Amendments.

            The provisions of this Article 13 shall not be amended or modified
without the written consent of the holders of all Senior Debt of the Company.

      Section 13.14. Subordination of Subsidiary Guarantees.

            Each Guarantor, the Trustee, and each Securityholder by accepting a
Security agrees, that the indebtedness and obligations under the Subsidiary
Guarantees (a) rank pari passu with the Guarantor's guarantees of the Existing
Senior Subordinated Securities and (b) are subordinated in right of payment, to
the extent and in the manner provided in this Article 13, to the prior payment
in full, in cash, of all Obligations with respect to Senior Debt of such
Guarantor (whether outstanding on the date hereof or hereafter created,
incurred, assumed or guaranteed), and that the subordination is for the benefit
of the holders of Senior Debt of such Guarantor.


                                       55
<PAGE>

      Section 13.15. Liquidation; Dissolution; Bankruptcy of a Guarantor.

            Upon any payment or distribution to creditors of any Guarantor in a
liquidation or dissolution of such Guarantor or in a bankruptcy, reorganization,
insolvency, receivership or similar proceeding relating to such Guarantor or its
property, in an assignment for the benefit of creditors or any marshaling of
such Guarantor's assets and liabilities:

                  (1) holders of Senior Debt of such Guarantor shall be entitled
            to receive payment in full in cash of all Obligations due in respect
            of such Senior Debt of such Guarantor (including interest after the
            commencement of any such proceeding at the rate specified in the
            applicable Senior Debt of such Guarantor, whether or not allowed as
            a claim in such proceeding) before the Securityholders shall be
            entitled to receive any payment or distribution from the Guarantor
            with respect to such Guarantor's Subsidiary Guarantee; and

                  (2) until all Obligations with respect to Senior Debt of such
            Guarantor (as provided in subsection (1) above) are paid in full in
            cash, any payment or distribution to which the Trustee or any
            Securityholder would be entitled but for this Article shall be made
            to holders of Senior Debt of such Guarantor, as their interests may
            appear.

      Section 13.16. Default on Senior Debt of the Guarantor.

            No Guarantor shall make any payment or distribution upon or in
respect of the Securities or its Subsidiary Guarantee, including, without
limitation, by way of set-off or otherwise, or redeem (or make a deposit in
redemption of), defease or acquire any of the Securities, for cash, properties
or securities if:

                  (i) a Payment Default with respect to Senior Debt of such
            Guarantor occurs and is continuing; or

                  (ii) a Non-Monetary Default on Senior Debt of such Guarantor
            occurs and is continuing that then permits holders of the Senior
            Debt of such Guarantor to accelerate its maturity and the Trustee
            receives a Payment Blockage Notice from a Person who may give it
            pursuant to Section 13.24 hereof. Any number of such Payment
            Blockage Notices may be given, provided, however, that (i) not more
            than one Payment Blockage Notice may be commenced during any period
            of 360 consecutive days and (ii) any default or event of default
            that existed or was continuing on the date of delivery of any
            Payment Blockage Notice to the Trustee (to the extent the holder of
            Designated Senior Debt, or such trustee or agent, giving such
            Payment Blockage Notice had knowledge of the same) shall not be the
            basis for a subsequent Payment Blockage Notice pursuant to Section
            13.24 herein, unless such default has been cured or waived for a
            period of not less than 90 consecutive days.


                                       56
<PAGE>

            Each Guarantor may and shall resume payments on and distributions in
respect of its Subsidiary Guarantee, the Securities and all Obligations with
respect thereto, and may acquire such Securities or Obligations upon the earlier
of:

                  (1) in the case of a payment default, the date upon which such
            default is cured or waived, or

                  (2) in the case of a Non-Monetary Default, on the earlier of
            the date on which such Non-Monetary Default is cured or waived or
            179 days after the date on which the applicable Payment Blockage
            Notice is received, if the maturity of such Senior Debt of such
            Guarantor has not been accelerated,

if this Article 13 otherwise permits the payment, distribution or acquisition at
the time thereof.

      Section 13.17. Acceleration of Securities; Duties of Guarantors.

            If payment of the Securities is accelerated because of an Event of
Default, each Guarantor shall promptly notify the Representative of the holders
of Senior Debt of such Guarantor of the acceleration.

      Section 13.18. When Distribution from Guarantor Must Be Paid Over.

            In the event that the Trustee or any Securityholder receives from a
Guarantor any payment of any Obligations with respect to the Securities or the
Subsidiary Guarantees at a time when the Trustee or such Securityholder, as
applicable, has actual knowledge that such payment is prohibited by Section
13.15 or 13.16 hereof, such payment shall be held by the Trustee or such
Securityholder, in trust for the benefit of, and shall be paid forthwith over
and delivered upon written request to, the holders of Senior Debt of such
Guarantor, as their interests may appear, or their Representative under the
indenture or other agreement (if any) pursuant to which Senior Debt of such
Guarantor may have been issued, as their respective interests may appear, for
application to the payment of all Obligations with respect to Senior Debt of
such Guarantor remaining unpaid to the extent necessary to pay such Obligations
in full in accordance with their terms, after giving effect to any concurrent
payment or distribution to or for the holders of Senior Debt of such Guarantor.

            With respect to the holders of Senior Debt of any Guarantor, the
Trustee undertakes to perform only such obligations on the part of the Trustee
as are specifically set forth in this Article 13, and no implied covenants or
obligations with respect to the holders of Senior Debt of such Guarantor shall
be read into this Indenture against the Trustee. The Trustee shall not be deemed
to owe any fiduciary duty to the holders of Senior Debt of such Guarantor, and
shall not be liable to any such holders if the Trustee shall pay over or
distribute to or on behalf of Securityholders or the Company or any other Person
money or assets to which any holders of Senior Debt of such Guarantor shall be
entitled by virtue of this Article 13, except if such payment is made as a
result of the willful misconduct or gross negligence of the Trustee.


                                       57
<PAGE>

      Section 13.19. Notice by a Guarantor.

            Each Guarantor shall promptly notify the Trustee and the Paying
Agent of any facts known to such Guarantor that would cause a payment of any
Obligations with respect to the Securities or its Subsidiary Guarantee to
violate this Article, but failure to give such notice shall not affect the
subordination of its Subsidiary Guarantee or of the Securities to the Senior
Debt of such Guarantor as provided in this Article 13.

      Section 13.20. Subrogation with Respect to Any Guarantor.

            With respect to any Guarantor, after all Obligations with respect to
Senior Debt of such Guarantor is paid in full, in cash, and until the Securities
are paid in full, Securityholders shall be subrogated (equally and ratably with
all other Indebtedness pari passu with such Guarantor's Subsidiary Guarantee) to
the rights of holders of Senior Debt of such Guarantor to receive distributions
applicable to Senior Debt of such Guarantor to the extent that distributions
otherwise payable to the Securityholders have been applied to the payment of
Senior Debt of such Guarantor. A distribution made under this Article to holders
of Senior Debt of such Guarantor that otherwise would have been made to
Securityholders is not, as between such Guarantor and Securityholders, a payment
by such Guarantor on the Securities or the Subsidiary Guarantee.

      Section 13.21. Relative Rights with Respect to Any Guarantor.

            This Article defines the relative rights of Securityholders and
holders of Senior Debt of each Guarantor. Nothing in this Indenture shall:

                  (1) impair, as between such Guarantor and the Securityholders,
            the obligation of such Guarantor, which is absolute and
            unconditional, to pay principal of and interest on the Securities in
            accordance with the terms of its Subsidiary Guarantee;

                  (2) affect the relative rights of Securityholders and
            creditors of such Guarantor other than their rights in relation to
            holders of Senior Debt of such Guarantor; or

                  (3) prevent the Trustee or any Securityholder from exercising
            its available remedies upon a Default or Event of Default, subject
            to the rights of holders of Senior Debt of such Guarantor set forth
            herein to receive distributions and payments otherwise payable to
            Securityholders.

            If any Guarantor fails because of this Article 13 to pay principal
of, premium or interest on a Security on the due date, the failure is still a
Default or Event of Default.

      Section 13.22. Subordination May Not Be Impaired By Any Guarantor.

            With respect to any Guarantor, no right of any holder of Senior Debt
of such Guarantor to enforce the subordination of the Indebtedness evidenced by
the Subsidiary


                                       58
<PAGE>

Guarantee shall be impaired by any act or failure to act by such Guarantor or
any Securityholder or by failure of such Guarantor or any Securityholder to
comply with this Indenture.

      Section 13.23. Distribution or Notice to Representative with Respect to
Any Guarantor.

            With respect to any Guarantor, whenever a distribution is to be made
or a notice given to holders of Senior Debt of such Guarantor, the distribution
may be made and the notice given to their Representative.

            Upon any payment or distribution of assets of any Guarantor referred
to in this Article 13, the Trustee and the Securityholders shall be entitled to
rely upon any order or decree made by any court of competent jurisdiction or
upon any certificate of such Representative or of the liquidating trustee or
agent or other Person making any distribution to the Trustee or to the
Securityholders for the purpose of ascertaining the Persons entitled to
participate in such distribution, the holders of the Senior Debt of such
Guarantor and other Indebtedness of such Guarantor, the amount or amounts
thereof or payable thereon, the amount or amounts paid or distributed thereon
and all other facts pertinent thereto or to this Article 13.

      Section 13.24. Rights of Trustee and Paying Agent with Respect to Any
Guarantor.

            Notwithstanding the provisions of this Article 13 or any other
provision of this Indenture, the Trustee shall not be charged with knowledge of
the existence of any facts that would prohibit the making of any payment or
distribution by the Trustee, and the Trustee and the Paying Agent may continue
to make payments on the Securities, unless the Trustee shall have received at
its Corporate Trust Office at least one Business Day prior to the date of such
payment a Payment Blockage Notice. Only the Representative of holders of
Designated Senior Debt may give a Payment Blockage Notice. Nothing in this
Article 13 shall impair the claims of, or payments to, the Trustee under or
pursuant to Section 7.7 hereof.

            With respect to any Guarantor, the Trustee in its individual or any
other capacity may hold Senior Debt of such Guarantor with the same rights it
would have if it were not Trustee. Any Agent may do the same with like rights.

      Section 13.25. Authorization to Effect Subordination with Respect to Any
Guarantor.

            Each Securityholder of a Security by the Securityholder's acceptance
thereof authorizes and directs the Trustee on the Securityholder's behalf to
take such action as may be necessary or appropriate to effectuate the
subordination as provided in this Article 13, and appoints the Trustee to act as
the Securityholder's attorney-in-fact for any and all such purposes. If the
Trustee does not file a proper proof of claim or proof of debt in the form
required in any proceeding relative to any Guarantor referred to in Section 6.4
hereof at least 30 days before the expiration of the time to file such claim,
the Representatives of Senior Debt of such Guarantor are hereby authorized to
file an appropriate claim for and on behalf of the Securityholders of the
Securities.


                                       59
<PAGE>

      Section 13.26. Amendments with Respect to Any Guarantor.

            With respect to any Guarantor, the provisions of Section 13.14
through 13.26 hereof shall not be amended or modified without the written
consent of the holders of all Senior Debt of such Guarantor.


                                       60
<PAGE>

            IN WITNESS WHEREOF, the parties hereto have caused this Indenture to
be duly executed as of the date and year first written above.

                         Iron Mountain Incorporated

                         By: /s/ C. Richard Reese
                             ----------------------------------------
                             Name: C. Richard Reese
                             Title: Chairman and Chief Executive Officer


                         Arcus Data Security, Inc.
                         COMAC, Inc.
                         DSI Technology Escrow Services, Inc.
                         IM Billerica, Inc.
                         Iron Mountain Global, Inc.
                         Iron Mountain Records Management, Inc.
                         Iron Mountain Records Management of Michigan, Inc.

                         By: /s/ C. Richard Reese
                             ----------------------------------------
                             Name: C. Richard Reese
                             Title: Chairman and Chief Executive Officer


                         Iron Mountain/National Underground Storage, LLC
                         Iron Mountain Consulting Services, LLC
                         Iron Mountain Confidential Destruction LLC

                         By: Iron Mountain Records Management, Inc.,
                             its sole Member

                              By: /s/ C. Richard Reese
                                  ----------------------------------------
                                  Name: C. Richard Reese
                                  Title: Chairman and Chief Executive Officer

                           [Indenture Signature Page]

<PAGE>

                                                                  EXECUTION COPY


                         Iron Mountain Global LLC

                         By: Iron Mountain Global, Inc., its sole Member

                              By: /s/ C. Richard Reese
                                  ----------------------------------------
                                  Name: C. Richard Reese
                                  Title: Chairman and Chief Executive Officer


                         Arcus Data Security LLC

                         By: Arcus Data Security, Inc., its sole Member

                             By: /s/ C. Richard Reese
                                 ----------------------------------------
                                 Name: C. Richard Reese
                                 Title: Chairman and Chief Executive Officer


                         THE BANK OF NEW YORK, as Trustee

                         By: /s/ Kisha A. Holder
                             --------------------------------------------------
                             Name: Kisha A. Holder
                             Title: Assistant Treasurer
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.2
<SEQUENCE>3
<FILENAME>a2049379zex-4_2.txt
<DESCRIPTION>EXHIBIT 4.2
<TEXT>

<PAGE>

                                                                  EXECUTION COPY

================================================================================

                           IRON MOUNTAIN INCORPORATED

                                      AND

                             THE BANK OF NEW YORK,
                                   as Trustee

                    8 5/8% Senior Subordinated Notes due 2013

                          FIRST SUPPLEMENTAL INDENTURE

                           Dated as of April 3, 2001

                                       TO

                             SUBORDINATED INDENTURE

                           Dated as of April 3, 2001

================================================================================

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                                TABLE OF CONTENTS

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ARTICLE 1. DEFINITIONS.........................................................1

   Section 1.1.    Definitions.................................................1

ARTICLE 2. FORM AND TERMS OF THE NOTES........................................19

   Section 2.1.    Form and Dating............................................19
   Section 2.2.    Execution and Authentication...............................20
   Section 2.3.    Depository and Paying Agent for Notes......................20
   Section 2.4.    Transfer and Exchange of Notes.............................20
   Section 2.5.    Redemption.................................................22
   Section 2.6.    Covenants..................................................25
      (a)  Reports............................................................25
      (b)  Restricted Payments................................................25
      (c)  Incurrence of Indebtedness and Issuance of Preferred Stock.........28
      (d)  Liens..............................................................29
      (e)  Dividend and Other Payment Restrictions Affecting Restricted
           Subsidiaries.......................................................29
      (f)  Transactions with Affiliates.......................................31
      (g)  Certain Senior Subordinated Debt...................................32
      (h)  Additional Subsidiary Guarantees...................................32
      (i)  Designation of Unrestricted Subsidiaries...........................33
      (j)  Limitation on Sale and Leaseback Transactions......................34
      (k)  Asset Sales........................................................35
      (l)  Change of Control Offer............................................37
      (m)  Corporate Existence................................................38
   Section 2.7.    Mergers, Consolidations or Sale of Assets..................39
   Section 2.8.    Events of Default..........................................40
   Section 2.9.    Acceleration...............................................41
   Section 2.10.   Amendments and Waivers.....................................42
   Section 2.11.   Subsidiary Guarantees......................................45
   Section 2.12.   Legal Defeasance and Covenant Defeasance...................45
   Section 2.13    Subordination..............................................45

ARTICLE 3. MISCELLANEOUS......................................................46

   Section 3.1.    Effect of Headings.........................................46
   Section 3.2.    Successors and Assigns.....................................46
   Section 3.3.    Separability Clause........................................47
   Section 3.4.    Governing Law..............................................47
   Section 3.5     First Supplement to Supersede Indenture....................47

EXHIBITS

Exhibit A         FORM OF NOTES
Exhibit B         FORM OF SUPPLEMENTAL INDENTURE
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<PAGE>

            THIS FIRST SUPPLEMENTAL INDENTURE, dated as of April 3, 2001 ("First
Supplemental Indenture"), is by and among IRON MOUNTAIN INCORPORATED, a
Pennsylvania corporation, having its principal office at 745 Atlantic Avenue,
Boston, Massachusetts 02111, the Guarantors signatory hereto and THE BANK OF NEW
YORK, a New York banking corporation, as trustee, having its principal corporate
trust office at 101 Barclay Street, 21st Floor, New York, NY 10286.

                                   WITNESSETH:

            WHEREAS, the Company and The Bank of New York, acting as trustee,
executed and delivered a Subordinated Indenture, dated as of April 3, 2001 (the
"Indenture"), to provide for the issuance by the Company from time to time of
Securities to be issued in one or more series as provided in the Indenture;

            WHEREAS, the issuance and sale of up to $500,000,000 aggregate
principal amount of a series of the Company's Securities (the "Notes") have been
authorized by resolutions adopted by the Board of Directors of the Company on
March 6, 2001;

            WHEREAS, the Company desires to issue and sell $225,000,000
aggregate principal amount of the Notes on the date hereof;

            WHEREAS, the Company desires to enter into this First Supplemental
Indenture pursuant to Section 9.1(e) of the Indenture to supplement the
Indenture to establish the form and terms of the Notes; and

            NOW, THEREFORE, for and in consideration of the premises stated
herein and the purchase of the Notes by the Holders thereof, the parties hereto
hereby enter into this First Supplemental Indenture, for the equal and
proportionate benefit of all Holders of Notes, as follows:

                                   ARTICLE 1.

                                   DEFINITIONS

Section 1.1. Definitions.

            (a) All of the terms used in this First Supplemental Indenture which
are defined in the Indenture shall have the meanings specified in the Indenture,
unless otherwise defined herein (in which case they shall have the meanings
defined herein for the purposes of the Indenture as well as for the First
Supplemental Indenture) or unless the context otherwise requires, and for the
purposes of this First Supplemental Indenture, the following terms have the
meanings set forth in this Section:

            "Acquired Debt" means, with respect to any specified Person:

            (1)   Indebtedness of any other Person, existing at the time such
                  other Person merged with or into or became a Subsidiary of
                  such specified Person, including Indebtedness incurred in
                  connection with, or in contemplation of, such other Person
                  merging with or into or becoming a Subsidiary of such
                  specified Person and

            (2)   Indebtedness encumbering any asset acquired by such specified
                  Person.

<PAGE>

            "Acquisition EBITDA" means, as of any date of determination, with
respect to an Acquisition EBITDA Entity, the sum of:

            (1)   EBITDA of such Acquisition EBITDA Entity for its last fiscal
                  quarter for which financial statements are available at such
                  date of determination (adjusted to give pro forma effect to
                  any acquisition or disposition of a business or Person by such
                  Acquisition EBITDA Entity consummated during the period
                  covered by, or after the date of, such quarterly financial
                  statements), multiplied by four (or if such quarterly
                  statements are not available, EBITDA for the most recent
                  fiscal year for which financial statements are available),
                  plus

            (2)   projected quantifiable improvements in operating results (on
                  an annualized basis) due to cost reductions calculated in good
                  faith by the Company or one of its Restricted Subsidiaries, as
                  certified by an Officers' Certificate filed with the Trustee,
                  without giving effect to any operating losses of the acquired
                  Person.

            "Acquisition EBITDA Entity" means, as of any date of determination,
a business or Person:

            (1)   which has been acquired by the Company or one of its
                  Restricted Subsidiaries and with respect to which financial
                  results on a consolidated basis with the Company have not been
                  made available for an entire fiscal quarter or

            (2)   which is to be acquired in whole or in part with Indebtedness,
                  the incurrence of which will require the calculation on such
                  date of the Acquisition EBITDA of such Acquisition EBITDA
                  Entity for purposes of Section 4.8 of the Indenture.

                  "Additional Notes" means up to $275,000,000 aggregate
principal amount of the Company's 8 5/8% Senior Subordinated Notes due 2013
(other than the Initial Notes) issued under this First Supplemental Indenture in
accordance with Section 2.2 hereof as part of the same series as the Initial
Notes.

            "Adjusted EBITDA" means, as of any date of determination and without
duplication, the sum of:

            (1)   EBITDA of the Company and its Restricted Subsidiaries for the
                  most recent fiscal quarter for which internal financial
                  statements are available at such date of determination,
                  multiplied by four and

            (2)   Acquisition EBITDA of each business or Person that is an
                  Acquisition EBITDA Entity as of such date of determination,
                  multiplied by a fraction, (i) the numerator of which is three
                  minus the number of months (and/or any portion thereof) in
                  such most recent fiscal quarter for which the financial
                  results of such Acquisition EBITDA Entity are included in the
                  EBITDA of the Company and its Restricted Subsidiaries under
                  clause (1) above, and (ii) the denominator of which is three.


                                       2
<PAGE>

The effects of unusual items, including merger-related expenses permitted to be
shown as a separate line item on a statement of operations in accordance with
GAAP, or non-recurring items in respect of the Company, a Restricted Subsidiary
or an Acquisition EBITDA Entity occurring in any period shall be excluded in the
calculation of Adjusted EBITDA.

            "Affiliate" of any specified Person means any other Person directly
or indirectly controlling or controlled by or under direct or indirect common
control with such specified Person. For purposes of this definition, "control"
(including, with correlative meanings, the terms "controlling," "controlled by"
and "under common control with"), as used with respect to any Person, shall mean
the possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of such Person, whether through the
ownership of voting securities, by agreement or otherwise; provided, however,
that beneficial ownership of 10% or more of the voting securities of a Person
shall be deemed to be control.

            "Agent Members" means members of, or participants in, the
Depository.

            "Attributable Indebtedness" in respect of a Sale and Leaseback
Transaction means, as of the time of determination, the greater of:

            (1)   the fair market value of the property subject to such
                  arrangement (as determined by the Board of Directors of the
                  Company) and

            (2)   the present value (discounted at the rate of interest implicit
                  in such transaction) of the total obligations of the lessee
                  for rental payments during the remaining terms of the lease
                  included in such Sale and Leaseback Transaction (including any
                  period for which such lease has been extended).

            "Capital Lease Obligation" means, at the time any determination
thereof is to be made, the amount of the liability in respect of a capital lease
that would at such time be so required to be capitalized on the balance sheet in
accordance with GAAP.

            "Capital Stock" means any and all shares, interests, participations,
rights or other equivalents (however designated) of corporate stock, including,
without limitation, with respect to partnerships, partnership interests (whether
general or limited) and any other interest or participation that confers on a
Person the right to receive a share of the profits and losses of, or
distributions of assets of, such partnership.

            "Cash Equivalents" means:

            (1)   securities with maturities of one year or less from the date
                  of acquisition, issued, fully guaranteed or insured by the
                  United States Government or any agency thereof;

            (2)   certificates of deposit, time deposits, overnight bank
                  deposits, bankers acceptances and repurchase agreements issued
                  by a Qualified Issuer having maturities of 270 days or less
                  from the date of acquisition;


                                       3
<PAGE>

            (3)   commercial paper of an issuer rated at least A-2 by Standard &
                  Poor's Rating Group, a division of McGraw Hill, Inc., or P-2
                  by Moody's Investors Service, or carrying an equivalent rating
                  by a nationally recognized rating agency if both of the two
                  named rating agencies cease publishing ratings of investments
                  and having maturities of 270 days or less from the date of
                  acquisition;

            (4)   money market accounts or funds with or issued by Qualified
                  Issuers; and

            (5)   Investments in money market funds substantially all of the
                  assets of which are comprised of securities and other
                  obligations of the types described in clauses (1) through (3)
                  above.

            "Change of Control" means the occurrence of any of the following
events:

            (1)   any "person" or "group" (as such terms are used in Sections
                  13(d) and 14(d) of the Exchange Act), other than the Principal
                  Stockholders (or any of them), is or becomes the "beneficial
                  owner" (as defined in Rules 13d-3 and 13d-5 under the Exchange
                  Act), directly or indirectly, of more than a majority of the
                  voting power of all classes of Voting Stock of the Company;

            (2)   the Company consolidates with, or merges with or into, another
                  Person or conveys, transfers, leases or otherwise disposes of
                  all or substantially all of its assets to any Person, or any
                  Person consolidates with, or merges with or into, the Company,
                  in any such event pursuant to a transaction in which the
                  outstanding Voting Stock of the Company is converted into or
                  exchanged for cash, securities or other property, other than
                  any such transaction where (i) the outstanding Voting Stock of
                  the Company is not converted or exchanged at all (except to
                  the extent necessary to reflect a change in the jurisdiction
                  of incorporation) or is converted into or exchanged for (A)
                  Voting Stock (other than Disqualified Stock) of the surviving
                  or transferee Person or (B) cash, securities and other
                  property (other than Capital Stock described in the foregoing
                  clause (A)) of the surviving or transferee Person in an amount
                  that could be paid as a Restricted Payment pursuant to Section
                  2.6(b) of this First Supplemental Indenture (Section 4.7 of
                  the Indenture) and (ii) immediately after such transaction, no
                  "person" or "group" (as such terms are used in Sections 13(d)
                  and 14(d) of the Exchange Act), other than the Principal
                  Stockholders (or any of them), is the "beneficial owner" (as
                  defined in Rules 13d-3 and 13d-5 under the Exchange Act),
                  directly or indirectly, of more than a majority of the total
                  outstanding Voting Stock of the surviving or transferee
                  Person;

            (3)   during any consecutive two-year period, individuals who at the
                  beginning of such period constituted the Board of Directors
                  (together with any new directors whose election to such Board
                  of Directors, or whose nomination for election by the
                  stockholders of the Company, was approved by a vote of 66 2/3%
                  of the directors then still in office who were either
                  directors at the beginning of such period or whose election or
                  nomination for election was previously so approved)


                                       4
<PAGE>

                  cease for any reason to constitute a majority of the Board of
                  Directors then in office; or

            (4)   the Company is liquidated or dissolved or adopts a plan of
                  liquidation or dissolution other than in a transaction which
                  complies with Section 2.7 of the First Supplemental Indenture
                  (Section 5.1 of the Indenture).

            "Consolidated Adjusted Net Income" means, for any period, the net
income (or net loss) of the Company and its Restricted Subsidiaries for such
period as determined on a consolidated basis in accordance with GAAP, adjusted
to the extent included in calculating such net income or loss by excluding:

            (1)   any net after-tax extraordinary gains or losses (less all fees
                  and expenses relating thereto);

            (2)   any net after-tax gains or losses (less all fees and expenses
                  relating thereto) attributable to Asset Sales;

            (3)   the portion of net income (or loss) of any Person (other than
                  the Company or a Restricted Subsidiary), including
                  Unrestricted Subsidiaries, in which the Company or any
                  Restricted Subsidiary has an ownership interest, except to the
                  extent of the amount of dividends or other distributions
                  actually paid to the Company or any Restricted Subsidiary in
                  cash dividends or distributions by such Person during such
                  period; and

            (4)   the net income (or loss) of any Person combined with the
                  Company or any Restricted Subsidiary on a "pooling of
                  interests" basis attributable to any period prior to the date
                  of combination.

            "Consolidated Income Tax Expense" means, for any period, the
provision for federal, state, local and foreign income taxes of the Company and
its Restricted Subsidiaries for such period as determined on a consolidated
basis in accordance with GAAP.

            "Consolidated Interest Expense" means, for any period, without
duplication, the sum of:

            (1)   the amount which, in conformity with GAAP, would be set forth
                  opposite the caption "interest expense" (or any like caption)
                  on a consolidated statement of operations of the Company and
                  its Restricted Subsidiaries for such period, including,
                  without limitation:

                  (i)   amortization of debt discount;

                  (ii)  the net cost of interest rate contracts (including
                        amortization of discounts);

                  (iii) the interest portion of any deferred payment obligation;

                  (iv)  amortization of debt issuance costs; and


                                       5
<PAGE>

                  (v)   the interest component of Capital Lease Obligations of
                        the Company and its Restricted Subsidiaries; plus

            (2)   all interest on any Indebtedness of any other Person
                  guaranteed and paid by the Company or any of its Restricted
                  Subsidiaries;

provided, however, that Consolidated Interest Expense will not include any gain
or loss from extinguishment of debt, including write-off of debt issuance costs.

            "Consolidated Non-Cash Charges" means, for any period, the aggregate
depreciation, amortization and other non-cash expenses of the Company and its
Restricted Subsidiaries (including without limitation any minority interest)
reducing Consolidated Adjusted Net Income for such period, determined on a
consolidated basis in accordance with GAAP (excluding any such non-cash charge
to the extent that it requires an accrual of or reserve for cash charges for any
future period).

            "Credit Agent" means The Chase Manhattan Bank, in its capacity as
administrative agent for the lenders party to the Credit Agreement, and The
Chase Manhattan Bank Canada, in its capacity as Canadian administrative agent
for the lenders party to the Credit Agreement, or any successor or successors
party thereto.

            "Credit Agreement" means that certain Fourth Amended and Restated
Credit Agreement dated as of August 14, 2000, as amended, among the Company, IM
Canada, the lenders party thereto and the Credit Agent, as further amended,
restated, supplemented, modified, renewed, refunded, increased, extended,
replaced or refinanced from time to time.

            "Default" means any event that is or with the passage of time or the
giving of notice or both would be an Event of Default.

            "Definitive Notes" means Notes that are in the form of the Notes
attached hereto as Exhibit A, that do not include the information called for by
Section 2.15 of the Indenture.

            "Designated Senior Debt" means:

            (1)   Senior Bank Debt and

            (2)   other Senior Debt the principal amount of which is $50.0
                  million or more at the date of designation by the Company in a
                  written instrument delivered to the Trustee.

Senior Debt designated as Designated Senior Debt pursuant to clause (2) shall
cease to be Designated Senior Debt at any time that the aggregate principal
amount thereof outstanding is $10.0 million or less.

            "Disqualified Stock" means any Capital Stock which, by its terms (or
by the terms of any security into which it is convertible or for which it is
exchangeable), or upon the happening of any event, matures or is mandatorily
redeemable, for cash or other property (other than Capital Stock that is not
Disqualified Stock) pursuant to a sinking fund obligation or otherwise, or is
redeemable at the option of the Holder thereof, in whole or in part, in each
case on or prior to the stated maturity of the Notes.


                                       6
<PAGE>

            "Dollars" and "$" mean lawful money of the United States of America.

            "EBITDA" means for any period Consolidated Adjusted Net Income for
such period increased by:

            (1)   Consolidated Interest Expense for such period; plus

            (2)   Consolidated Income Tax Expense for such period; plus

            (3)   Consolidated Non-Cash Charges for such period.

            "Equity Interests" means Capital Stock and all warrants, options or
other rights to acquire Capital Stock (but excluding any debt security that is
convertible into, or exchangeable for, Capital Stock).

            "Equity Proceeds" means:

            (1)   with respect to Equity Interests (or debt securities converted
                  into Equity Interests) issued or sold for cash Dollars, the
                  aggregate amount of such cash Dollars and

            (2)   with respect to Equity Interests (or debt securities converted
                  into Equity Interests) issued or sold for any consideration
                  other than cash Dollars, the aggregate Market Price thereof
                  computed on the date of the issuance or sale thereof.

            "Excluded Restricted Subsidiary" means any Restricted Subsidiary
organized under the laws of a jurisdiction other than the United States (as
defined in Regulation S under the Securities Act) and that has not delivered a
Subsidiary Guarantee.

            "Existing Indebtedness" means Indebtedness of the Company and its
Subsidiaries (other than under the Credit Agreement) in existence on the date of
the Indenture, until such amounts are repaid.

            "Global Note" means a permanent global Note that contains the
paragraph referred to in Section 2.15 of the Indenture and the additional
Schedule of Exchanges of Notes to the form of the Note attached hereto as
Exhibit A, and that is deposited with and registered in the name of the
Depository.

            "Government Securities" means direct obligations of, or obligations
guaranteed by, the United States of America for the payment of which guarantee
or obligations the full faith and credit of the United States of America is
pledged.

            "Guarantee" means, as applied to any obligation:

            (1)   a guarantee (other than by endorsement of negotiable
                  instruments for collection in the ordinary course of
                  business), direct or indirect, in any manner, of any part or
                  all of such obligation; and


                                       7
<PAGE>

            (2)   an agreement, direct or indirect, contingent or otherwise, the
                  practical effect of which is to assure in any way the payment
                  or performance (or payment of damages in the event of
                  non-performance) of all or any part of such obligation,
                  including, without limiting the foregoing, the obligation to
                  reimburse amounts drawn down under letters of credit securing
                  such obligations.

            "Hedging Obligations" means, with respect to any Person, the
obligations of such Person under:

            (1)   interest rate swap agreements, interest rate cap agreements
                  and interest rate collar agreements and

            (2)   other agreements or arrangements designed to protect such
                  Person against fluctuations in interest rates.

            "IM Canada" means Iron Mountain Canada Corporation, a Wholly Owned
Subsidiary of the Company, formerly known as Pierce Leahy Canada Company.

            "Indebtedness" means (without duplication), with respect to any
Person, whether recourse is to all or a portion of the assets of such Person,
and whether or not contingent:

            (1)   every obligation of such Person for money borrowed;

            (2)   every obligation of such Person evidenced by bonds,
                  debentures, notes or other similar instruments;

            (3)   every reimbursement obligation of such Person with respect to
                  letters of credit, bankers' acceptances or similar facilities
                  issued for the account of such Person;

            (4)   every obligation of such Person issued or assumed as the
                  deferred purchase price of property or services;

            (5)   every Capital Lease Obligation and every obligation of such
                  Person in respect of Sale and Leaseback Transactions that
                  would be required to be capitalized on the balance sheet in
                  accordance with GAAP;

            (6)   all Disqualified Stock of such Person valued at the greater of
                  its voluntary or involuntary maximum fixed repurchase price,
                  plus accrued and unpaid dividends (unless included in such
                  maximum repurchase price);

            (7)   all obligations of such Person under or with respect to
                  Hedging Obligations which would be required to be reflected on
                  the balance sheet as a liability of such Person in accordance
                  with GAAP; and

            (8)   every obligation of the type referred to in clauses (1)
                  through (7) of another Person and dividends of another Person
                  the payment of which, in either case, such Person has
                  guaranteed.


                                       8
<PAGE>

            For purposes of this definition, the "maximum fixed repurchase
price" of any Disqualified Stock that does not have a fixed repurchase price
shall be calculated in accordance with the terms of such Disqualified Stock as
if such Disqualified Stock were repurchased on any date on which Indebtedness is
required to be determined pursuant to the First Supplemental Indenture, and if
such price is based upon, or measured by, the fair market value of such
Disqualified Stock, such fair market value shall be determined in good faith by
the board of directors of the issuer of such Disqualified Stock. Notwithstanding
the foregoing, trade accounts payable and accrued liabilities arising in the
ordinary course of business and any liability for federal, state or local taxes
or other taxes owed by such Person shall not be considered Indebtedness for
purposes of this definition. The amount outstanding at any time of any
Indebtedness issued with original issue discount is the aggregate principal
amount at maturity of such Indebtedness, less the remaining unamortized portion
of the original issue discount of such Indebtedness at such time, as determined
in accordance with GAAP.

            "Initial Notes" means the first $225,000,000 aggregate principal
amount of 8 5/8% Senior Subordinated Notes due 2013 that are issued under the
First Supplemental Indenture, as amended or supplemented from time to time
pursuant to the Indenture.

            "Investments" means, with respect to any Person, all investments by
such Person in other Persons (including Affiliates) in the forms of loans
(including Guarantees), advances or capital contributions (excluding commission,
travel and similar advances to officers and employees made in the ordinary
course of business), purchases or other acquisitions for consideration of
Indebtedness, Equity Interests or other securities and all other items that are
or would be classified as investments on a balance sheet prepared in accordance
with GAAP.

            "Leverage Ratio" means, at any date, the ratio of:

            (1)   the aggregate principal amount of Indebtedness of the Company
                  and its Restricted Subsidiaries outstanding as of the most
                  recent available quarterly or annual balance sheet, to

            (2)   Adjusted EBITDA, after giving pro forma effect, without
                  duplication, to

                  (i)   the incurrence, repayment or retirement of any
                        Indebtedness by the Company or its Restricted
                        Subsidiaries since the last day of the most recent full
                        fiscal quarter of the Company;

                  (ii)  if the Leverage Ratio is being determined in connection
                        with the incurrence of Indebtedness by the Company or a
                        Restricted Subsidiary, such Indebtedness; and

                  (iii) the Indebtedness to be incurred in connection with the
                        acquisition of any Acquisition EBITDA Entity.

            "Lien" means, with respect to any asset, any mortgage, lien, pledge,
charge, security interest or encumbrance of any kind in respect of such asset,
whether or not filed, recorded or otherwise perfected under applicable law
(including any conditional sale or other title retention agreement, any lease in
the nature thereof, any option or other agreement to sell or give a security
interest in and any


                                       9
<PAGE>

filing of or agreement to give any financing statement under the Uniform
Commercial Code, or equivalent statutes, of any jurisdiction).

            "Make-Whole Amount" means, with respect to any Note, an amount equal
to the excess, if any, of:

            (1)   the present value of the remaining principal, premium and
                  interest payments that would be payable with respect to such
                  Note if such Note were redeemed on April 1, 2006, computed
                  using a discount rate equal to the Treasury Rate plus 75 basis
                  points over

            (2)   the outstanding principal amount of such Note.

            "Make-Whole Average Life" means, with respect to any date of
redemption of Notes, the number of years (calculated to the nearest one-twelfth)
from such redemption date to April 1, 2006.

            "Make-Whole Price" means, with respect to any Note, the greater of:

            (1)   the sum of the principal amount of and Make-Whole Amount with
                  respect to such Note and

            (2)   the redemption price of such Note on April 1, 2006.

            "Market Price" means:

            (1)   with respect to the calculation of Equity Proceeds from the
                  issuance or sale of debt securities which have been converted
                  into Equity Interests, the value received upon the original
                  issuance or sale of such converted debt securities, as
                  determined reasonably and in good faith by the Board of
                  Directors and

            (2)   with respect to the calculation of Equity Proceeds from the
                  issuance or sale of Equity Interests, the average of the daily
                  closing prices for such Equity Interests for the 20
                  consecutive trading days preceding the date of such
                  computation.

            The closing price for each day shall be:

            (1)   if such Equity Interests are then listed or admitted to
                  trading on the New York Stock Exchange, the closing price on
                  the NYSE Consolidated Tape (or any successor consolidated tape
                  reporting transactions on the New York Stock Exchange) or, if
                  such composite tape shall not be in use or shall not report
                  transactions in such Equity Interests, or if such Equity
                  Interests shall be listed on a stock exchange other than the
                  New York Stock Exchange (including for this purpose the Nasdaq
                  National Market), the last reported sale price regular way for
                  such day, or in case no such reported sale takes place on such
                  day, the average of the closing bid and asked prices regular
                  way for such day, in each case on the principal national
                  securities exchange on which such Equity Interests are listed
                  or admitted to trading (which shall be the national securities
                  exchange on which the


                                       10
<PAGE>

                  greatest number of such Equity Interests have been traded
                  during such 20 consecutive trading days); or

            (2)   if such Equity Interests are not listed or admitted to trading
                  on any such exchange, the average of the closing bid and asked
                  prices thereof in the over-the-counter market as reported by
                  the National Association of Securities Dealers Automated
                  Quotation System or any successor system, or if not included
                  therein, the average of the closing bid and asked prices
                  thereof furnished by two members of the National Association
                  of Securities Dealers selected reasonably and in good faith by
                  the Board of Directors for that purpose. In the absence of one
                  or more such quotations, the Market Price for such Equity
                  Interests shall be determined reasonably and in good faith by
                  the Board of Directors.

            "Net Proceeds" means the aggregate cash proceeds received by the
Company or any of its Restricted Subsidiaries in respect of any Asset Sale,
which amount is equal to the excess, if any, of:

            (1)   the cash received by the Company or such Restricted Subsidiary
                  (including any cash payments received by way of deferred
                  payment pursuant to, or monetization of, a note or installment
                  receivable or otherwise, but only as and when received) in
                  connection with such disposition, over

            (2)   the sum of:

                  (i)   the amount of any Indebtedness which is secured by such
                        asset and which is required to be repaid in connection
                        with the disposition thereof; plus

                  (ii)  the reasonable out-of-pocket expenses incurred by the
                        Company or such Restricted Subsidiary, as the case may
                        be, in connection with such disposition or in connection
                        with the transfer of such amount from such Restricted
                        Subsidiary to the Company; plus

                  (iii) provisions for taxes, including income taxes,
                        attributable to the disposition of such asset or
                        attributable to required prepayments or repayments of
                        Indebtedness with the proceeds thereof; plus

                  (iv)  if the Company does not first receive a transfer of such
                        amount from the relevant Restricted Subsidiary with
                        respect to the disposition of an asset by such
                        Restricted Subsidiary and such Restricted Subsidiary
                        intends to make such transfer as soon as practicable,
                        the out-of-pocket expenses and taxes that the Company
                        reasonably estimates will be incurred by the Company or
                        such Restricted Subsidiary in connection with such
                        transfer at the time such transfer is expected to be
                        received by the Company (including, without limitation,
                        withholding taxes on the remittance of such amount).


                                       11
<PAGE>

            "Notes" has the meaning assigned to it in the preamble to this First
Supplemental Indenture. The Initial Notes and any Additional Notes shall be
treated as a single class for all purposes under this First Supplemental
Indenture and the Indenture.

            "Obligations" means any principal, interest (including post-petition
interest, whether or not allowed as a claim in any proceeding), penalties, fees,
costs, expenses, indemnifications, reimbursements, damages and other liabilities
payable under or in connection with any Indebtedness.

            "Officers' Certificate" means a certificate signed, unless otherwise
specified, by any two of the Chairman of the Board, a Vice Chairman of the
Board, the President, the Chief Financial Officer, the Controller, or an
Executive Vice President of the Company, and delivered to the Trustee.

            "Permitted Investments" means:

            (1)   any Investments in the Company or in a Restricted Subsidiary
                  (other than an Excluded Restricted Subsidiary) of the Company,
                  including without limitation the Guarantee of Indebtedness
                  permitted under Section 2.6(c) of the First Supplemental
                  Indenture (Section 4.8 of the Indenture);

            (2)   any Investments in Cash Equivalents;

            (3)   Investments by the Company or any Restricted Subsidiary of the
                  Company in a Person, if as a result of such Investment;

                  (i)   such Person becomes a Restricted Subsidiary (other than
                        an Excluded Restricted Subsidiary) of the Company or

                  (ii)  such Person is merged, consolidated or amalgamated with
                        or into, or transfers or conveys substantially all of
                        its assets to, or is liquidated into, the Company or a
                        Restricted Subsidiary (other than an Excluded Restricted
                        Subsidiary) of the Company;

            (4)   Investments in assets (including accounts and notes
                  receivable) owned or used in the ordinary course of business;

            (5)   Investments for any purpose related to the Company's records
                  and information management business (including, without
                  limitation, the Company's confidential destruction and
                  fulfillment businesses) in an aggregate outstanding amount not
                  to exceed $10.0 million; and

            (6)   Investments by the Company or a Restricted Subsidiary (other
                  than an Excluded Restricted Subsidiary) in one or more
                  Excluded Restricted Subsidiaries, the aggregate outstanding
                  amount of which does not exceed 10% of the consolidated assets
                  of the Company and its Restricted Subsidiaries.

            "Permitted Liens" means:

            (1)   Liens existing as of the date hereof;


                                       12
<PAGE>

            (2)   Liens on property or assets of the Company or any Restricted
                  Subsidiary securing Senior Debt;

            (3)   Liens on any property or assets of a Restricted Subsidiary
                  granted in favor of the Company or any Wholly Owned Restricted
                  Subsidiary;

            (4)   Liens securing the Notes or the Guarantees;

            (5)   any interest or title of a lessor under any Capital Lease
                  Obligation or Sale and Leaseback Transaction so long as the
                  Indebtedness, if any, secured by such Lien does not exceed the
                  principal amount of Indebtedness permitted under Section
                  2.6(c) of the First Supplemental Indenture (Section 4.8 of the
                  Indenture);

            (6)   Liens securing Acquired Debt created prior to (and not in
                  connection with or in contemplation of) the incurrence of such
                  Indebtedness by the Company or any Restricted Subsidiary;
                  provided that such Lien does not extend to any property or
                  assets of the Company or any Restricted Subsidiary other than
                  the assets acquired in connection with the incurrence of such
                  Acquired Debt;

            (7)   Liens securing Hedging Obligations permitted to be incurred
                  pursuant to clause (7) of Section 2.6(c) of the First
                  Supplemental Indenture (clause (7) of Section 4.8 of the
                  Indenture);

            (8)   Liens arising from purchase money mortgages and purchase money
                  security interests, or in respect of the construction of
                  property or assets, incurred in the ordinary course of the
                  business of the Company or a Restricted Subsidiary; provided
                  that (i) the related Indebtedness is not secured by any
                  property or assets of the Company or any Restricted Subsidiary
                  other than the property and assets so acquired or constructed
                  and (ii) the Lien securing such Indebtedness is created within
                  60 days of such acquisition or construction;

            (9)   statutory Liens or landlords' and carriers', warehousemen's,
                  mechanics', suppliers', materialmen's, repairmen's or other
                  like Liens arising in the ordinary course of business and with
                  respect to amounts not yet delinquent or being contested in
                  good faith by appropriate proceedings, if a reserve or other
                  appropriate provision, if any, as is then required in
                  conformity with GAAP shall have been made therefor;

            (10)  Liens for taxes, assessments, government charges or claims
                  with respect to amounts not yet delinquent or that are being
                  contested in good faith by appropriate proceedings diligently
                  conducted, if a reserve or other appropriate provision, if
                  any, as is required in conformity with GAAP has been made
                  therefor;

            (11)  Liens incurred or deposits made to secure the performance of
                  tenders, bids, leases, statutory obligations, surety and
                  appeal bonds, government contracts, performance bonds and
                  other obligations of a like nature incurred in the ordinary
                  course of business (other than contracts for the payment of
                  money);


                                       13
<PAGE>

            (12)  easements, rights-of-way, restrictions and other similar
                  charges or encumbrances not interfering in any material
                  respect with the business of the Company or any Restricted
                  Subsidiary incurred in the ordinary course of business;

            (13)  Liens arising by reason of any judgment, decree or order of
                  any court so long as such Lien is adequately bonded and any
                  appropriate legal proceedings that may have been duly
                  initiated for the review of such judgment, decree or order
                  shall not have been finally terminated or the period within
                  which such proceedings may be initiated shall not have
                  expired;

            (14)  Liens arising under options or agreements to sell assets;

            (15)  other Liens securing obligations incurred in the ordinary
                  course of business, which obligations do not exceed $10.0
                  million in the aggregate at any one time outstanding; and

            (16)  any extension, renewal or replacement, in whole or in part, of
                  any Lien described in the foregoing clauses (1) through (15);
                  provided that any such extension, renewal or replacement shall
                  not extend to any additional property or assets.

            "Person" means any individual, corporation, limited liability
company, partnership, joint venture, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

            "Principal Stockholders" means each of Vincent J. Ryan, Schooner
Capital LLC, C. Richard Reese, Kent P. Dauten, B. Thomas Golisano and their
respective Affiliates.

            "Qualified Equity Offering" means an offering of Capital Stock,
other than Disqualified Stock, of the Company for Dollars, whether registered or
exempt from registration under the Securities Act.

            "Qualified Issuer" means:

            (1)   any lender party to the Credit Agreement or

            (2)   any commercial bank:

                  (i)   which has capital and surplus in excess of $500,000,000
                        and

                  (ii)  the outstanding short-term debt securities of which are
                        rated at least A-2 by Standard & Poor's Rating Group, a
                        division of McGraw-Hill, Inc. or at least P-2 by Moody's
                        Investors Service, or carry an equivalent rating by a
                        nationally recognized rating agency if both of the two
                        named rating agencies cease publishing ratings of
                        investments.

            "Qualifying Sale and Leaseback Transaction" means any Sale and
Leaseback Transaction between the Company or any of its Restricted Subsidiaries
and any bank, insurance company or other lender or investor providing for the
leasing to the Company or such Restricted Subsidiary of any


                                       14
<PAGE>

property (real or personal) which has been or is to be sold or transferred by
the Company or such Restricted Subsidiary to such lender or investor or to any
Person to whom funds have been or are to be advanced by such lender or investor
and where the property in question has been constructed or acquired after the
date of the First Supplemental Indenture.

            "Refinancing Indebtedness" means new Indebtedness incurred or given
in exchange for, or the proceeds of which are used to repay, redeem, defease,
extend, refinance, renew, replace or refund, other Indebtedness; provided,
however, that:

            (1)   the principal amount of such new Indebtedness shall not exceed
                  the principal amount of Indebtedness so repaid, redeemed,
                  defeased, extended, refinanced, renewed, replaced or refunded
                  (plus the amount of fees, premiums, consent fees, prepayment
                  penalties and expenses incurred in connection therewith);

            (2)   such Refinancing Indebtedness shall have a Weighted Average
                  Life to Maturity equal to or greater than the Weighted Average
                  Life to Maturity of the Indebtedness so repaid, redeemed,
                  defeased, extended, refinanced, renewed, replaced or refunded
                  or shall mature after the maturity date of the Notes;

            (3)   to the extent such Refinancing Indebtedness refinances
                  Indebtedness that has a final maturity date occurring after
                  the initial scheduled maturity date of the Notes, such new
                  Indebtedness shall have a final scheduled maturity not earlier
                  than the final scheduled maturity of the Indebtedness so
                  repaid, redeemed, defeased, extended, refinanced, renewed,
                  replaced or refunded and shall not permit redemption at the
                  option of the holder earlier than the earliest date of
                  redemption at the option of the holder of the Indebtedness so
                  repaid, redeemed, defeased, extended, refinanced, renewed,
                  replaced or refunded;

            (4)   to the extent such Refinancing Indebtedness refinances
                  Indebtedness subordinate to the Notes, such Refinancing
                  Indebtedness shall be subordinated in right of payment to the
                  Notes and to the extent such Refinancing Indebtedness
                  refinances Notes or Indebtedness pari passu with the Notes,
                  such Refinancing Indebtedness shall be pari passu with or
                  subordinated in right of payment to the Notes, in each case on
                  terms at least as favorable to the holders of Notes as those
                  contained in the documentation governing the Indebtedness so
                  repaid, redeemed, defeased, extended, refinanced, renewed,
                  replaced or refunded; and

            (5)   with respect to Refinancing Indebtedness incurred by a
                  Restricted Subsidiary, such Refinancing Indebtedness shall
                  rank no more senior, and shall be at least as subordinated, in
                  right of payment to the Subsidiary Guarantee of such
                  Restricted Subsidiary as the Indebtedness being extended,
                  refinanced, renewed, replaced or refunded.


                                       15
<PAGE>

            "Restricted Subsidiary" means:

            (1)   each direct or indirect Subsidiary of the Company existing on
                  the date of the First Supplemental Indenture (other than Iron
                  Mountain (Netherlands) B.V. and its subsidiaries (including
                  Iron Mountain Europe Limited), Iron Mountain Cayman Ltd. and
                  its subsidiaries, Iron Mountain Mexico, S.A. de R.L. de C.V.,
                  PLRH Inc. and Upper Providence Venture I, L.P.) and

            (2)   any other direct or indirect Subsidiary of the Company formed,
                  acquired or existing after the date of the First Supplemental
                  Indenture (including an Excluded Restricted Subsidiary),

which, in the case of (1) or (2), is not designated by the Board of Directors as
an "Unrestricted Subsidiary."

            "Sale and Leaseback Transaction" means any transaction or series of
related transactions pursuant to which a Person sells or transfers any property
or asset in connection with the leasing, or the resale against installment
payments, of such property or asset to the seller or transferor.

            "Senior Bank Debt" means all Obligations outstanding under or in
connection with the Credit Agreement (including Guarantees of such Obligations
by Subsidiaries of the Company).

            "Senior Debt" means:

            (1)   the Senior Bank Debt and

            (2)   any other Indebtedness permitted to be incurred by the Company
                  or any Restricted Subsidiary, as the case may be, under the
                  terms of the First Supplemental Indenture or the Indenture,
                  unless the instrument under which such Indebtedness is
                  incurred expressly provides that it is:

                  (i)   on a parity with or subordinated in right of payment to
                        the Notes or

                  (ii)  subordinated to Senior Debt on terms substantially
                        similar to those of the Notes.

            Notwithstanding anything to the contrary in the foregoing, Senior
Debt shall not include:

            (1)   any liability for federal, state, local or other taxes owed or
                  owing by the Company;

            (2)   any Indebtedness of the Company to any of its Subsidiaries or
                  other Affiliates;

            (3)   any trade payables; or

            (4)   any Indebtedness that is incurred in violation of the First
                  Supplemental Indenture or the Indenture, provided that such
                  Indebtedness shall be deemed not to have been incurred in
                  violation of the First Supplemental Indenture or the Indenture
                  for purposes of this clause (4) if, in the case of any
                  obligations under the Credit


                                       16
<PAGE>

                  Agreement, the holders of such obligations or their agent or
                  representative shall have received a representation from the
                  Company to the effect that the incurrence of such Indebtedness
                  does not violate the provisions of the First Supplemental
                  Indenture or the Indenture.

            "Significant Subsidiary" means any Subsidiary that would be a
"significant subsidiary" as defined in Article 1, Rule 1-02 of Regulation S-X,
promulgated pursuant to the Securities Act, as such Regulation is in effect on
the date hereof.

            "Subsidiary" means, with respect to any Person, any corporation,
association or other business entity of which more than 50% of the total voting
power of shares of Capital Stock entitled (without regard to the occurrence of
any contingency) to vote in the election of directors, managers or trustees
thereof is at the time owned or controlled, directly or indirectly, by such
Person or one or more of the other Subsidiaries of such Person or a combination
thereof.

            "Treasury Rate" means, at any time of computation, the yield to
maturity at such time (as compiled by and published in the most recent Federal
Reserve Statistical Release H.15(519), which has become publicly available at
least two business days prior to the date of the redemption notice or, if such
Statistical Release is no longer published, any publicly available source of
similar market data) of United States Treasury securities with a constant
maturity most nearly equal to the Make-Whole Average Life; provided, however,
that if the Make-Whole Average Life is not equal to the constant maturity of the
United States Treasury security for which a weekly average yield is given, the
Treasury Rate shall be obtained by linear interpolation (calculated to the
nearest one-twelfth of a year) from the weekly average yields of United States
Treasury securities for which such yields are given, except that if the
Make-Whole Average Life is less than one year, the weekly average yield on
actually traded United States Treasury securities adjusted to a constant
maturity of one year shall be used.

            "Unrestricted Subsidiary" means:

            (1)   any Subsidiary that is designated by the Board of Directors as
                  an Unrestricted Subsidiary in accordance with Section 2.6(i)
                  of the First Supplemental Indenture (Section 4.14 of the
                  Indenture) and

            (2)   any Subsidiary of an Unrestricted Subsidiary.

As of the date hereof, the following Subsidiaries of the Company have been
designated as Unrestricted Subsidiaries: Iron Mountain (Netherlands) B.V. and
its subsidiaries (including Iron Mountain Europe Limited), Iron Mountain Cayman
Ltd. and its subsidiaries, Iron Mountain Mexico, S.A. de R.L. de C.V., PLRH Inc.
and Upper Providence Venture I, L.P.

            "Voting Stock" means any class or classes of Capital Stock pursuant
to which the holders thereof have the general voting power under ordinary
circumstances to elect at least a majority of the board of directors, managers
or trustees of any Person (irrespective of whether or not, at the time, stock of
any other class or classes has, or might have, voting power by reason of the
happening of any contingency).

            "Weighted Average Life to Maturity" means, when applied to any
Indebtedness at any date, the number of years obtained by dividing:


                                       17
<PAGE>

            (1)   the sum of the products obtained by multiplying (x) the amount
                  of each then remaining installment, sinking fund, serial
                  maturity or other required payment of principal, including
                  payment at final maturity, in respect thereof, by (y) the
                  number of years (calculated to the nearest one-twelfth) that
                  will elapse between such date and the making of such payment,
                  by

            (2)   the then outstanding principal amount of such Indebtedness.

            "Wholly Owned Restricted Subsidiary" means any Restricted Subsidiary
of the Company all of the outstanding Capital Stock or other ownership interests
of which (other than directors' qualifying shares) shall at the time be owned by
the Company or by one or more Wholly Owned Restricted Subsidiaries of the
Company.

            "1996 Indenture Date" means October 1, 1996.

            "1999 Indenture Date" means April 26, 1999.

            "8 1/8% Notes" means IM Canada's 8 1/8% Senior Notes due 2008 issued
pursuant to the Indenture dated as of April 7, 1998, by and among IM Canada, as
issuer, the Company and The Bank of New York, as trustee. The 8 1/8% Notes have
been guaranteed by the Company and certain of its Subsidiaries (including,
without limitation, the Guarantors) on a senior subordinated basis.

            "8 1/4% Notes" means the Company's 8 1/4% Senior Subordinated Notes
due 2011 issued pursuant to the Indenture dated April 26, 1999, by and among the
Company, certain of its subsidiaries and The Bank of New York, as trustee.

            "8 3/4% Notes" means the Company's 8 3/4% Senior Subordinated Notes
due 2009 issued pursuant to the Indenture dated October 24, 1997, by and among
the Company, certain of its subsidiaries and The Bank of New York, as trustee.

            "9 1/8% Notes" means the Company's 9 1/8% Senior Subordinated Notes
due 2007, issued pursuant to the Indenture dated as of July 7, 1997, by and
between the Company, as issuer, and The Bank of New York, as trustee.

            "10 1/8% Notes" means the Company's 10 1/8% Senior Subordinated
Notes due 2006 issued pursuant to the Indenture dated October 1, 1996, by and
among the Company, certain of its subsidiaries and First Bank National
Association, as trustee.

            "11 1/8% Notes" means the Company's 11 1/8% Senior Subordinated
Notes due 2006 issued pursuant to the Indenture dated as of July 15, 1996,
between the Company, as issuer, and United States Trust Company of New York, as
trustee.

            (b)   Other Definitions.

            The definitions of the following terms may be found in the Sections
indicated as follows:

<TABLE>
<CAPTION>
                  Term                                        Defined in Section

                  <S>                                         <C>
                  "Affiliate Transaction"                     2.6(f)


                                       18
<PAGE>

                  "Asset Sale"                                2.6(k)
                  "Asset Sale Offer"                          2.6(k)
                  "Bankruptcy Law"                            2.8
                  "Change of Control Offer"                   2.6(l)
                  "Change of Control Payment"                 2.6(l)
                  "Change of Control Payment Date"            2.6(l)
                  "Commencement Date"                         2.6(k)
                  "Custodian"                                 2.8
                  "DTC"                                       2.3
                  "Event of Default"                          6.1
                  "Excess Proceeds"                           2.6(k)
                  "First Supplemental Indenture"              Preamble
                  "incur"                                     2.6(c)
                  "Indenture"                                 Preamble
                  "Restricted Payments"                       2.6(b)
</TABLE>

                                   ARTICLE 2.

                           FORM AND TERMS OF THE NOTES

Section 2.1. Form and Dating.(a) General. The Notes and the Trustee's
certificate of authentication shall be substantially in the form of Exhibit A
attached hereto. The Notes may have notations, legends or endorsements required
by law, stock exchange rule or usage. Each Note shall be dated the date of its
authentication. The Notes shall be in denominations of $1,000 and integral
multiples thereof.

            The terms and provisions contained in the Notes shall constitute,
and are hereby expressly made, a part of the First Supplemental Indenture and
the Indenture and the Company, the Guarantors and the Trustee, by their
execution and delivery of the First Supplemental Indenture and the Indenture (or
in the case of any Guarantor that becomes such after the date hereof, a
supplemental indenture pursuant to Section 2.6(h) of this First Supplemental
Indenture (Section 4.13 of the Indenture)), expressly agree to such terms and
provisions and to be bound thereby.

            (b) Global Notes. Notes shall be issued initially in the form of the
Global Notes, which shall be deposited on behalf of the purchasers of the Notes
represented thereby with the Depository at its New York office, and registered
in the name of the Depository or a nominee of the Depository, duly executed by
the Company and authenticated by the Trustee as hereinafter provided. The
aggregate principal amount of the Global Notes may from time to time be
increased or decreased by adjustments made on the records of the Trustee and the
Depository or its nominee as hereinafter provided.

            The Global Notes shall represent such of the outstanding Notes as
shall be specified therein and shall provide that it shall represent the
aggregate amount of outstanding Notes from time to time endorsed thereon and
that the aggregate amount of outstanding Notes represented thereby may from time
to time be reduced or increased, as appropriate, to reflect exchanges and
redemptions. Any endorsement of the Global Notes to reflect the amount of any
increase or decrease in the amount of outstanding Notes represented thereby
shall be made by the Trustee or the Service Agent, at the direction of the
Trustee, in accordance with instructions given by the Holder thereof as required
by Section 2.4 of this First Supplemental Indenture.


                                       19
<PAGE>

            Except as set forth in Section 2.4 of this First Supplemental
Indenture, the Global Notes may be transferred, in whole and not in part, only
to another nominee of the Depository or to a successor of the Depository or its
nominee.

            (c) Book-Entry Provisions. This Section 2.1(c) shall apply only to
the Global Notes deposited with or on behalf of the Depository.

            The Company shall execute and the Trustee shall, in accordance with
this Section 2.1(c), authenticate and deliver the Global Notes that (i) shall be
registered in the name of the Depository or the nominee of the Depository and
(ii) shall be delivered by the Trustee to the Depository or pursuant to the
Depository's instructions or held by the Service Agent.

            Agent Members shall have no rights either under the First
Supplemental Indenture or the Indenture with respect to any Global Notes held on
their behalf by the Depository or by the Service Agent or under such Global
Notes, and the Depository may be treated by the Company, the Trustee and any
agent of the Company or the Trustee as the absolute owner of such Global Notes
for all purposes whatsoever.

            (d) Definitive Notes. Notes issued in certificated form shall be
substantially in the form of Exhibit A attached hereto (but without including
the text referred to in Section 2.15.3 of the Indenture). Except as provided in
Section 2.4, owners of beneficial interests in the Global Notes will not be
entitled to receive physical delivery of certificated Securities.

Section 2.2. Execution and Authentication.

            The Trustee shall, upon a written order of the Company signed by an
Officer, authenticate up to $225,000,000 aggregate principal amount of Initial
Notes and up to $275,000,000 of Additional Notes.

Section 2.3. Depository and Paying Agent for Notes.

            The Company initially appoints The Depository Trust Company ("DTC")
to act as Depository with respect to the Global Notes. The Company initially
appoints the Trustee to act as the Registrar, Paying Agent and Service Agent
with respect to the Global Notes.

Section 2.4. Transfer and Exchange of Notes.

            (a) Transfer and Exchange of Beneficial Interests in Global Notes.
The transfer and exchange of beneficial interests in the Global Notes shall be
effected through the Depository, in accordance with the First Supplemental
Indenture and the Indenture and the procedures of the Depository therefor.
Beneficial interests in the Global Notes may be transferred to Persons who take
delivery thereof in the form of a beneficial interest in the Global Notes.

            (b) Transfer and Exchange of Definitive Notes. When Definitive Notes
are presented by a Holder to the Registrar with a request:

                  (x)   to register the transfer of the Definitive Notes; or


                                       20
<PAGE>

                  (y)   to exchange such Definitive Notes for an equal principal
                        amount of Definitive Notes of other authorized
                        denominations,

the Registrar shall register the transfer or make the exchange as requested if
its requirements for such transactions are met; provided, however, that the
Definitive Notes presented or surrendered for register of transfer or exchange
shall be duly endorsed or accompanied by a written instruction of transfer in
form satisfactory to the Registrar duly executed by such Holder or by his
attorney, duly authorized in writing.

            (c) Restrictions on Transfer and Exchange of Global Notes.
Notwithstanding any other provision of the First Supplemental Indenture or the
Indenture (other than the provisions set forth in subsection (d) of this Section
2.4), the Global Notes may not be transferred as a whole except by the
Depository to a nominee of the Depository or by a nominee of the Depository to
the Depository or another nominee of the Depository or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository.

            (d) Authentication of Definitive Notes in Absence of Depository. If
at any time:

                  (i)   the Depository for the Notes notifies the Company that
                        the Depository is unwilling or unable to continue as
                        Depository for the Global Notes and a successor
                        Depository for the Global Notes is not appointed by the
                        Company within 90 days after delivery of such notice; or

                  (ii)  the Company at its sole discretion, notifies the Trustee
                        in writing that it elects to cause the issuance of
                        Definitive Notes under the First Supplemental Indenture
                        and the Indenture,

then the Company shall execute, and the Trustee shall, upon receipt of an
authentication order in accordance with Section 2.2 hereof, authenticate and
deliver, Definitive Notes in an aggregate principal amount equal to the
principal amount of the Global Notes in exchange for such Global Notes.

            (e) Cancellation and/or Adjustment of the Global Notes. At such time
as all beneficial interests in the Global Notes have been exchanged for
Definitive Notes, redeemed, repurchased or canceled, the Global Notes shall be
returned to or retained and canceled by the Trustee in accordance with Section
2.12 of the Indenture. At any time prior to such cancellation, if any beneficial
interest in the Global Notes is exchanged for Definitive Notes, redeemed,
repurchased or canceled, the aggregate principal amount of Notes represented by
the Global Notes shall be reduced accordingly and an endorsement shall be made
on the Global Notes, by the Trustee or the Service Agent, at the direction of
the Trustee, to reflect such reduction. A Definitive Note may be exchanged for a
beneficial interest in the Global Note only upon receipt by the Trustee of a
Definitive Note, duly endorsed or accompanied by appropriate instruments of
transfer, in form satisfactory to the Trustee, together with written
instructions directing the Trustee to make an endorsement on the Global Note to
reflect an increase in the aggregate principal amount of the Notes represented
by the Global Note; in which case the Trustee shall cancel such Definitive Note
and cause the aggregate principal amount of Notes represented by the Global Note
to be increased accordingly. If no Global Note is then outstanding, the Company
shall issue and the Trustee shall authenticate a new Global Note in the
appropriate principal amount.

            (f) General Provisions Relating to Transfers and Exchanges.


                                       21
<PAGE>

                  (i)   To permit registrations of transfers and exchanges, the
                        Company shall execute and the Trustee shall authenticate
                        Definitive Notes and the Global Notes at the Registrar's
                        request.

                  (ii)  No service charge shall be made to a Holder for any
                        registration of transfer or exchange, but the Company
                        may require payment of a sum sufficient to cover any
                        transfer tax or similar governmental charge payable in
                        connection therewith (other than any such transfer taxes
                        or similar governmental charge payable upon exchange or
                        transfer pursuant to Section 2.4 of this First
                        Supplemental Indenture).

                  (iii) All Definitive Notes and the Global Notes issued upon
                        any registration of transfer or exchange of Definitive
                        Notes or the Global Notes shall be the valid obligations
                        of the Company, evidencing the same debt, and entitled
                        to the same benefits under the First Supplemental
                        Indenture and the Indenture, as the Definitive Notes or
                        the Global Notes surrendered upon such registration of
                        transfer or exchange.

                  (iv)  Prior to due presentment for the registration of a
                        transfer of any Note, the Trustee, any Agent, the
                        Company and any Guarantor may deem and treat the Person
                        in whose name any Note is registered as the absolute
                        owner of such Note for all purposes, including receiving
                        payment of principal of and interest on such Notes, and
                        neither the Trustee, any Agent, the Company nor any
                        Guarantor shall be affected by notice to the contrary.

                  (v)   The Trustee shall authenticate Definitive Notes and the
                        Global Notes in accordance with the provisions of
                        Section 2.2 of the First Supplemental Indenture and
                        Section 2.3 of the Indenture.

Section 2.5. Redemption.

            With respect to the Notes issued under this First Supplemental
Indenture, the following Sections supplement Article III of the Indenture:

            Section 3.7. Optional Redemption.

            Prior to April 1, 2006, the Notes shall be subject to redemption at
any time at the option of the Company, in whole or in part, upon not less than
30 nor more than 60 days' notice, at the Make-Whole Price, plus accrued and
unpaid interest, to but excluding the applicable redemption date. On and after
April 1, 2006, the Notes will be subject to redemption at any time at the option
of the Company, in whole or in part, upon not less than 30 nor more than 60
days' notice, at the redemption prices (expressed as percentages of principal
amount) set forth below, plus accrued and unpaid interest, to but excluding the
applicable redemption date, if redeemed during the twelve-month period beginning
on April 1 of the years indicated below:

<TABLE>
<CAPTION>
             Year                                                     Percentage
             ----                                                     ----------

             <S>                                                      <C>
             2006................................................       104.313%


                                       22
<PAGE>

             2007................................................       102.875%
             2008................................................       101.438%
             2009 and thereafter.................................       100.000%
</TABLE>

            Notwithstanding the foregoing, at any time prior to April 1, 2004,
the Company may redeem up to 35% of the initial principal amount of the Notes
originally issued with the net proceeds of one or more Qualified Equity
Offerings at a redemption price equal to 108.625% of the principal amount of
such Notes, plus accrued and unpaid interest to but excluding the redemption
date; provided, that at least 65% of the principal amount of Notes originally
issued remains outstanding immediately after the occurrence of any such
redemption and that such redemption occurs within 60 days following the closing
of any such Qualified Equity Offering.

            Section 3.8. Mandatory Redemption.

            The Company shall not be required to make mandatory redemption
payments or sinking fund payments with respect to the Notes.

            Section 3.9. Asset Sale Offers.

            In the event that the Company shall commence an Asset Sale Offer
pursuant to Section 4.16 hereof, it shall follow the procedures specified below:

            The Asset Sale Offer shall remain open for 20 Business Days after
the Commencement Date relating to such Asset Sale Offer, except to the extent
required to be extended by applicable law (as so extended, the "Offer Period").
No later than one Business Day after the termination of the Offer Period (the
"Purchase Date"), the Company shall purchase the principal amount (the "Offer
Amount") of Notes required to be purchased in such Asset Sale Offer pursuant to
Sections 3.2 and 4.16 hereof or, if less than the Offer Amount has been
tendered, all Notes tendered in response to the Asset Sale Offer.

            If the Purchase Date is on or after an interest payment record date
and on or before the related interest payment date, any interest accrued to such
Purchase Date shall be paid to the Person in whose name a Note is registered at
the close of business on such record date, and no additional interest shall be
payable to Holders who tender Notes pursuant to the Asset Sale Offer.

            On the Commencement Date of any Asset Sale Offer, the Company shall
send or cause to be sent, by first class mail, a notice to each of the Holders,
with a copy to the Trustee. Such notice, which shall govern the terms of the
Asset Sale Offer, shall contain all instructions and materials necessary to
enable the Holders to tender Notes pursuant to the Asset Sale Offer and shall
state:

            (1)   that the Asset Sale Offer is being made pursuant to this
                  Section 3.9 and Section 4.16 hereof and the length of time the
                  Asset Sale Offer shall remain open;

            (2)   the Offer Amount, the purchase price and the Purchase Date;

            (3)   that any Note not tendered or accepted for payment shall
                  continue to accrue interest;


                                       23
<PAGE>

            (4)   that, unless the Company defaults in the payment of the
                  purchase price, any Note accepted for payment pursuant to the
                  Asset Sale Offer shall cease to accrue interest after the
                  Purchase Date;

            (5)   that Holders electing to have a Note purchased pursuant to any
                  Asset Sale Offer shall be required to surrender the Note, with
                  the form entitled "Option of Holder to Elect Purchase" on the
                  reverse of the Note completed, to the Company, a depositary,
                  if appointed by the Company, or a Paying Agent at the address
                  specified in the notice prior to the close of business on the
                  Business Day preceding the Purchase Date;

            (6)   that Holders shall be entitled to withdraw their election if
                  the Company, depositary or Paying Agent, as the case may be,
                  receives, not later than the close of business on the Business
                  Day preceding the termination of the Offer Period, a facsimile
                  transmission or letter setting forth the name of the Holder,
                  the principal amount of the Note the Holder delivered for
                  purchase and a statement that such Holder is withdrawing such
                  Holder's election to have the Note purchased;

            (7)   that, if the aggregate principal amount of Notes surrendered
                  by Holders exceeds the Offer Amount, the Trustee shall select
                  the Notes to be purchased on a pro rata basis (with such
                  adjustments as may be deemed appropriate by the Company so
                  that only Notes in denominations of $1,000, or integral
                  multiples thereof, shall be purchased); and

            (8)   that Holders whose Notes were purchased only in part shall be
                  issued new Notes equal in principal amount to the unpurchased
                  portion of the Notes surrendered.

            On or before 12:00 noon on each Purchase Date, the Company shall
irrevocably deposit with the Trustee or Paying Agent in immediately available
funds the aggregate purchase price with respect to a principal amount of Notes
equal to the Offer Amount, together with accrued interest thereon, to be held
for payment in accordance with the terms of this Section 3.9. On the Purchase
Date, the Company shall, to the extent lawful, (i) accept for payment, on a pro
rata basis to the extent necessary, an aggregate principal amount equal to the
Offer Amount of Notes and other notes (in accordance with the terms of Section
4.16 of the Indenture) tendered pursuant to the Asset Sale Offer, or if less
than the Offer Amount has been tendered, all Notes and such other notes or
portions thereof tendered, (ii) deliver or cause the Paying Agent or depositary,
as the case may be, to deliver to the Trustee Notes so accepted and (iii)
deliver to the Trustee an Officers' Certificate stating that such Notes or
portions thereof were accepted for payment by the Company in accordance with the
terms of this Section 3.9. The Company, depositary or Paying Agent, as the case
may be, shall promptly (but in any case not later than three Business Days after
the Purchase Date) mail or deliver to each tendering Holder an amount equal to
the purchase price with respect to the Notes tendered by such Holder and
accepted by the Company for purchase, and the Company shall promptly issue a new
Note, and the Trustee shall authenticate and mail or deliver such new Note, to
such Holder, equal in principal amount to any unpurchased portion of such
Holder's Notes surrendered. Any Note not accepted in the Asset Sale Offer shall
be promptly mailed or delivered by the Company to the Holder thereof. The
Company shall publicly announce in a newspaper of general circulation the
results of the Asset Sale Offer on the Purchase Date.


                                       24
<PAGE>

            The Asset Sale Offer shall be made by the Company in compliance with
all applicable laws, including, without limitation, Regulation 14E of the
Exchange Act and the rules thereunder, to the extent applicable, and all other
applicable federal and state securities laws.

            Each purchase pursuant to this Section 3.9 shall be made pursuant to
the provisions of the second paragraph of Section 3.5 hereof to the extent
applicable.

            In the event the amount of Excess Proceeds to be applied to an Asset
Sale Offer would result in the purchase of a principal amount of Notes which is
not evenly divisible by $1,000, the Trustee shall promptly refund to the Company
the portion of such Excess Proceeds that is not necessary to purchase the
immediately lesser principal amount of Notes that is so divisible.

Section 2.6. Covenants.

            With respect to the Notes issued under this First Supplemental
Indenture, Section (a) below replaces Section 4.2 of the Indenture, Section (m)
below replaces Section 4.5 of the Indenture and each other Section is added to
Article IV of the Indenture.

            (a) Reports.

            Section 4.2. Reports. Whether or not required by the rules and
regulations of the SEC, so long as any Notes are outstanding, the Company
will furnish to the Holders of Notes:

            (1)   all quarterly and annual financial information that would be
                  required to be contained in a filing with the SEC on Forms
                  10-Q and 10-K if the Company were required to file such Forms,
                  including a "Management's Discussion and Analysis of Financial
                  Condition and Results of Operations" and, with respect to the
                  annual information only, a report thereon by the Company's
                  certified independent accountants and

            (2)   all financial information that would be required to be
                  included in a Form 8-K filed with the SEC if the Company were
                  required to file such reports.

In addition, whether or not required by the rules and regulations of the SEC,
the Company will file a copy of all such information and reports with the SEC
for public availability (unless the SEC will not accept such a filing) and make
such information available to investors who request it in writing.

            (b) Restricted Payments.

            Section 4.7. Restricted Payments. The Company shall not, and
shall not permit any of its Restricted Subsidiaries to, directly or
indirectly:

            (1)   declare or pay any dividend or make any distribution on
                  account of the Company's or any of its Restricted
                  Subsidiaries' Equity Interests (other than dividends or
                  distributions payable in Equity Interests (other than
                  Disqualified Stock) of the Company or such Restricted
                  Subsidiary or dividends or distributions payable to the
                  Company or any Restricted Subsidiary);


                                       25
<PAGE>

            (2)   purchase, redeem or otherwise acquire or retire for value any
                  Equity Interests of the Company or any Restricted Subsidiary
                  or other Affiliate of the Company (other than any such Equity
                  Interests owned by the Company or any Restricted Subsidiary);

            (3)   purchase, redeem or otherwise acquire or retire prior to
                  scheduled maturity for value any Indebtedness that is
                  subordinated in right of payment to the Notes; or

            (4)   make any Investment other than a Permitted Investment (all
                  such payments and other actions set forth in clauses (1)
                  through (4) above being collectively referred to as
                  "Restricted Payments");

unless, at the time of such Restricted Payment:

                  (i)   no Default or Event of Default shall have occurred and
                        be continuing or would occur as a consequence thereof;
                        and

                  (ii)  the Company would, at the time of such Restricted
                        Payment and after giving pro forma effect thereto, have
                        been permitted to incur at least $1.00 of additional
                        Indebtedness pursuant to the test set forth in the first
                        paragraph of Section 4.8 of the Indenture; and

                  (iii) such Restricted Payment, together with the aggregate of
                        all other Restricted Payments made by the Company and
                        its Restricted Subsidiaries after the 1996 Indenture
                        Date is less than (x) the cumulative EBITDA of the
                        Company, minus 1.75 times the cumulative Consolidated
                        Interest Expense of the Company, in each case for the
                        period (taken as one accounting period) from June 30,
                        1996, to the end of the Company's most recently ended
                        fiscal quarter for which internal financial statements
                        are available at the time of such Restricted Payment,
                        plus (y) the aggregate net Equity Proceeds received by
                        the Company from the issuance or sale since the 1996
                        Indenture Date of Equity Interests of the Company or of
                        debt securities of the Company that have been converted
                        into such Equity Interests (other than Equity Interests
                        or convertible debt securities sold to a Restricted
                        Subsidiary of the Company and other than Disqualified
                        Stock or debt securities that have been converted into
                        Disqualified Stock), plus (z) $2.0 million.

            The foregoing provisions will not prohibit:

            (1)   the payment of any dividend within 60 days after the date of
                  declaration thereof, if at said date of declaration such
                  payment would have complied with the provisions of the
                  Indenture;

            (2)   the redemption, repurchase, retirement or other acquisition or
                  retirement for value of any Equity Interests of the Company in
                  exchange for, or with the net cash proceeds of, the
                  substantially concurrent sale (other than to a Restricted


                                       26
<PAGE>

                  Subsidiary of the Company) of other Equity Interests of the
                  Company (other than any Disqualified Stock);

            (3)   the defeasance, redemption, repurchase, retirement or other
                  acquisition or retirement for value of Indebtedness that is
                  subordinated in right of payment to the Notes in exchange for,
                  or with the net cash proceeds of, a substantially concurrent
                  issuance and sale (other than to a Restricted Subsidiary of
                  the Company) of Equity Interests of the Company (other than
                  Disqualified Stock);

            (4)   the defeasance, redemption, repurchase, retirement or other
                  acquisition or retirement for value of Indebtedness that is
                  subordinated in right of payment to the Notes in exchange for,
                  or with the net cash proceeds of, a substantially concurrent
                  issue and sale (other than to the Company or any of its
                  Restricted Subsidiaries) of Refinancing Indebtedness;

            (5)   the repurchase of any Indebtedness subordinated in right of
                  payment to the Notes at a purchase price not greater than 101%
                  of the principal amount of such Indebtedness in the event of a
                  Change of Control in accordance with provisions similar to the
                  covenant set forth in Section 2.6(l) of the First Supplemental
                  Indenture (Section 4.17 of the Indenture), provided that prior
                  to or contemporaneously with such repurchase the Company has
                  made the Change of Control Offer as provided in such covenant
                  with respect to the Notes and has repurchased all Notes
                  validly tendered for payment in connection with such Change of
                  Control Offer; and

            (6)   additional payments to current or former employees or
                  directors of the Company for repurchases of stock, stock
                  options or other equity interests, provided that the aggregate
                  amount of all such payments under this clause (6) does not
                  exceed $0.5 million in any year and $2.0 million in the
                  aggregate.

            The Restricted Payments described in clauses (2), (3), (5) and (6)
of the immediately preceding paragraph will be Restricted Payments that shall be
permitted to be taken in accordance with such paragraph but shall reduce the
amount that would otherwise be available for Restricted Payments under clause
(iii) of the first paragraph of this Section, and the Restricted Payments
described in clauses (1) and (4) of the immediately preceding paragraph shall be
Restricted Payments that shall be permitted to be taken in accordance with such
paragraph and shall not reduce the amount that would otherwise be available for
Restricted Payments under clause (iii) of the first paragraph of this Section.

            If an Investment results in the making of a Restricted Payment, the
aggregate amount of all Restricted Payments deemed to have been made as
calculated under the foregoing provision shall be reduced by the amount of any
net reduction in such Investment (resulting from the payment of interest or
dividends, loan repayment, transfer of assets or otherwise) to the extent such
net reduction is not included in the Company's EBITDA; provided, however, that
the total amount by which the aggregate amount of all Restricted Payments may be
reduced may not exceed the lesser of (a) the cash proceeds received by the
Company and its Restricted Subsidiaries in connection with such net reduction
and (b) the initial amount of such Investment.


                                       27
<PAGE>

            If the aggregate amount of all Restricted Payments calculated under
the foregoing provision includes an Investment in an Unrestricted Subsidiary or
other Person that thereafter becomes a Restricted Subsidiary, such Investment
will no longer be counted as a Restricted Payment for purposes of calculating
the aggregate amount of Restricted Payments. For the purpose of making any
calculations under the Indenture:

            (1)   an Investment will include the fair market value of the net
                  assets of any Restricted Subsidiary at the time that such
                  Restricted Subsidiary is designated an Unrestricted Subsidiary
                  and will exclude the fair market value of the net assets of
                  any Unrestricted Subsidiary that is designated as a Restricted
                  Subsidiary;

            (2)   any property transferred to or from an Unrestricted Subsidiary
                  will be valued at fair market value at the time of such
                  transfer, provided that, in each case, the fair market value
                  of an asset or property is as determined by the Board of
                  Directors in good faith and

            (3)   subject to the foregoing, the amount of any Restricted
                  Payment, if other than cash, will be determined by the Board
                  of Directors, whose good faith determination will be
                  conclusive.

            The Board of Directors may designate a Restricted Subsidiary to be
an Unrestricted Subsidiary in compliance with the Section 4.14 of the Indenture.
Upon such designation, all outstanding Investments by the Company and its
Restricted Subsidiaries (except to the extent repaid in cash) in the Subsidiary
so designated will be deemed to be Restricted Payments made at the time of such
designation and will reduce the amount available for Restricted Payments under
the first paragraph of this covenant. Such designation will only be permitted if
such Restricted Payment would be permitted at such time and if such Restricted
Subsidiary otherwise meets the definition of an Unrestricted Subsidiary.

            (c) Incurrence of Indebtedness and Issuance of Preferred Stock.

            Section 4.8. Incurrence of Indebtedness and Issuance of Preferred
Stock. The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, issue, assume,
guaranty or otherwise become directly or indirectly liable with respect to
(collectively, "incur") any Indebtedness (including Acquired Debt) and the
Company shall not permit any of its Restricted Subsidiaries to issue any
shares of preferred stock; provided, however, that the Company may incur
Indebtedness and may permit a Restricted Subsidiary to incur Indebtedness if
at the time of such incurrence and after giving effect thereto the Leverage
Ratio would be less than 6.5 to 1.0.

            The foregoing limitations shall not apply to:

            (1)   the incurrence by the Company or any Restricted Subsidiary of
                  Senior Bank Debt in an aggregate amount not to exceed $100.0
                  million at any one time outstanding;

            (2)   the issuance by the Restricted Subsidiaries of Subsidiary
                  Guarantees;

            (3)   the incurrence by the Company and its Restricted Subsidiaries
                  of the Existing Indebtedness;


                                       28
<PAGE>

            (4)   the issuance by the Company of the Notes;

            (5)   the incurrence by the Company and its Restricted Subsidiaries
                  of Capital Lease Obligations and/or additional Indebtedness
                  constituting purchase money obligations up to an aggregate of
                  $5.0 million at any one time outstanding, provided that the
                  Liens securing such Indebtedness constitute Permitted Liens;

            (6)   the incurrence of Indebtedness between (i) the Company and its
                  Restricted Subsidiaries and (ii) the Restricted Subsidiaries;

            (7)   Hedging Obligations that are incurred for the purpose of
                  fixing or hedging interest rate risk with respect to any
                  floating rate Indebtedness that is permitted by the terms of
                  the Indenture to be outstanding;

            (8)   the incurrence by the Company and its Restricted Subsidiaries
                  of Indebtedness arising out of letters of credit, performance
                  bonds, surety bonds and bankers' acceptances incurred in the
                  ordinary course of business up to an aggregate of $5.0 million
                  at any one time outstanding;

            (9)   the incurrence by the Company and its Restricted Subsidiaries
                  of Indebtedness consisting of guarantees, indemnities or
                  obligations in respect of purchase price adjustments in
                  connection with the acquisition or disposition of assets,
                  including, without limitation, shares of Capital Stock; and

            (10)  the incurrence by the Company and its Restricted Subsidiaries
                  of Refinancing Indebtedness issued in exchange for, or the
                  proceeds of which are used to repay, redeem, defease, extend,
                  refinance, renew, replace or refund, Indebtedness referred to
                  in clauses (2) through (5) above, and this clause (10) or that
                  was otherwise permitted to be incurred pursuant to the test
                  set forth in the first paragraph of this Section 4.8.

            (d) Liens.

            Section 4.9. Liens. Neither the Company nor any of its Restricted
Subsidiaries may directly or indirectly create, incur, assume or suffer to
exist any Lien (other than a Permitted Lien) upon any property or assets now
owned or hereafter acquired, or any income, profits or proceeds therefrom, or
assign or otherwise convey any right to receive income therefrom, unless (a)
in the case of any Lien securing any Indebtedness that is subordinate to the
Notes, the Notes are secured by a Lien on such property, assets or proceeds
that is senior in priority to such Lien and (b) in the case of any other
Lien, the Notes are equally and ratably secured with the obligation or
liability secured by such Lien.

            (e) Dividend and Other Payment Restrictions Affecting Restricted
Subsidiaries.

            Section 4.10. Dividend and Other Payment Restrictions Affecting
Restricted Subsidiaries. The Company shall not, and shall not permit any of
its Restricted Subsidiaries to, directly or indirectly, create or otherwise
cause or suffer to exist or become effective any encumbrance or restriction
on the ability of any Restricted Subsidiary to:

                                       29
<PAGE>

            (1)   (i) pay dividends or make any other distributions to the
                  Company or any of its Restricted Subsidiaries (A) on its
                  Capital Stock or (B) with respect to any other interest or
                  participation in, or measured by, its profits, or (ii) pay any
                  Indebtedness owed to the Company or any of its Restricted
                  Subsidiaries;

            (2)   make loans or advances to the Company or any of its Restricted
                  Subsidiaries; or

            (3)   transfer any of its properties or assets to the Company or any
                  of its Restricted Subsidiaries.

            However, the preceding restrictions will not apply to encumbrances
or restrictions existing under or by reason of:

            (1)   Existing Indebtedness;

            (2)   the Credit Agreement as in effect as of the date of the
                  Indenture, and any amendments, modifications, restatements,
                  renewals, increases, supplements, refundings, replacements or
                  refinancing thereof, provided that such amendments,
                  modifications, restatements, renewals, increases, supplements,
                  refundings, replacements or refinancings are no more
                  restrictive in the aggregate with respect to such dividend and
                  other payment restrictions than those contained in the Credit
                  Agreement as in effect on the date of the Indenture;

            (3)   the Indenture and the Notes;

            (4)   applicable law;

            (5)   any instrument governing Indebtedness or Capital Stock of a
                  Person acquired by the Company or any of its Restricted
                  Subsidiaries as in effect at the time of such acquisition
                  (except to the extent such Indebtedness was incurred in
                  connection with or in contemplation of such acquisition),
                  which encumbrance or restriction is not applicable to any
                  Person, or the properties or assets of any Person, other than
                  the Person, or the property or assets of the Person, so
                  acquired, provided that the EBITDA of such Person is not taken
                  into account in determining whether such acquisition was
                  permitted by the terms of the Indenture;

            (6)   customary non-assignment provisions in leases entered into in
                  the ordinary course of business and consistent with past
                  practices;

            (7)   restrictions on the transfer of property subject to purchase
                  money obligations or Capital Lease Obligations otherwise
                  permitted by clause (5) of Section 4.8 of the Indenture;

            (8)   permitted Refinancing Indebtedness, provided that the
                  restrictions contained in the agreements governing such
                  Refinancing Indebtedness are no more restrictive in the
                  aggregate than those contained in the agreements governing the
                  Indebtedness being refinanced; or


                                       30
<PAGE>

            (9)   any agreement or instrument governing Indebtedness of an
                  Excluded Restricted Subsidiary provided that (i) at the time
                  such agreement or instrument is entered into, such Excluded
                  Restricted Subsidiary and its Restricted Subsidiaries have a
                  Leverage Ratio of less than 6.5 to 1.0 and (ii) neither such
                  Excluded Restricted Subsidiary nor any of its Restricted
                  Subsidiaries shall, directly or indirectly, incur any
                  Indebtedness (including Acquired Debt) unless at the time of
                  such incurrence and after giving effect thereto, the Leverage
                  Ratio for such Excluded Restricted Subsidiary and its
                  Restricted Subsidiaries would be less than 6.5 to 1.0. For
                  purposes of determining the Leverage Ratio under this clause
                  (9) only, all references to the "Company" and its "Restricted
                  Subsidiaries" or similar references in the definition of
                  "Leverage Ratio" and other defined terms necessary to
                  determine the Leverage Ratio shall be deemed to refer to such
                  Excluded Restricted Subsidiary and its Restricted
                  Subsidiaries, respectively.

            (f) Transactions with Affiliates.

                Section 4.11. Transactions with Affiliates. The Company shall
not, and shall not permit any of its Restricted Subsidiaries to, sell, lease,
transfer or otherwise dispose of any of its properties or assets to, or
purchase any property or assets from, or enter into any contract, agreement,
understanding, loan, advance or guarantee with, or for the benefit of, any
Affiliate (each of the foregoing, an "Affiliate Transaction"), unless:

            (a)   such Affiliate Transaction is on terms that are no less
                  favorable to the Company or the relevant Restricted Subsidiary
                  than those that would have been obtained in a comparable
                  transaction by the Company or such Restricted Subsidiary with
                  a non-Affiliated Person and

            (b)   the Company delivers to the Trustee:

                  (i)   with respect to any Affiliate Transaction involving
                        aggregate payments in excess of $5.0 million, a
                        resolution of the Board of Directors set forth in an
                        Officers' Certificate certifying that such Affiliate
                        Transaction complies with clause (a) above and such
                        Affiliate Transaction is approved by a majority of the
                        disinterested members of the Board of Directors and

                  (ii)  with respect to any Affiliate Transaction involving
                        aggregate payments in excess of $10.0 million, an
                        opinion as to the fairness to the Company or such
                        Restricted Subsidiary from a financial point of view
                        issued by an investment banking firm of national
                        standing.

            The following items shall not be deemed Affiliate Transactions and
therefore, will not be subject to the provisions of the prior paragraph:

            (1)   any employment agreement entered into by the Company or any of
                  its Restricted Subsidiaries in the ordinary course of business
                  and consistent with the past practice of the Company or such
                  Restricted Subsidiary;


                                       31
<PAGE>

            (2)   transactions between or among the Company and/or its
                  Restricted Subsidiaries;

            (3)   transactions permitted by the provisions of Section 4.7 of the
                  Indenture; and

            (4)   the grant of stock, stock options or other equity interests to
                  employees and directors of the Company and any Restricted
                  Subsidiary in accordance with duly adopted Company stock
                  grant, stock option and similar plans.

            The provisions set forth in clause (b) above shall not apply to
sales of inventory by the Company or any Restricted Subsidiary to any Affiliate
in the ordinary course of business. The provisions of clause (b) (ii) above
shall not apply to loans or advances to the Company or any Restricted Subsidiary
from, or equity investments in the Company or any Restricted Subsidiary by, any
Affiliate to the extent permitted by the provisions of Section 4.8 of the
Indenture.

            (g) Certain Senior Subordinated Debt.

            Section 4.12. Certain Senior Subordinated Debt. The Company shall
not incur any Indebtedness that is subordinated or junior in right of payment
to any Senior Debt of the Company and senior in any respect in right of
payment to the Notes. The Company shall not permit any Restricted Subsidiary
to incur any Indebtedness that is subordinated or junior in right of payment
to its Senior Debt and senior in any respect in right of payment to its
Subsidiary Guarantee.

            (h) Additional Subsidiary Guarantees.

            Section 4.13. Additional Subsidiary Guarantees. If any entity
(other than an Excluded Restricted Subsidiary) shall become a Restricted
Subsidiary after the date of the First Supplemental Indenture, then such
Restricted Subsidiary shall execute a supplemental indenture in the form of
Exhibit B attached hereto, pursuant to which it shall provide a Subsidiary
Guarantee, and deliver an Opinion of Counsel with respect thereto, in
accordance with the terms of the Indenture.

            No Restricted Subsidiary (including any Excluded Restricted
Subsidiary) shall consolidate with or merge with or into (whether or not such
Restricted Subsidiary is the surviving Person), another Person (other than the
Company) whether or not affiliated with such Restricted Subsidiary unless:

            (1)   subject to the provisions of the immediately following
                  sentence, the Person formed by or surviving any such
                  consolidation or merger (if other than such Restricted
                  Subsidiary) assumes all the obligations of such Restricted
                  Subsidiary under its Subsidiary Guarantee (except in the case
                  of an Excluded Restricted Subsidiary) pursuant to a
                  supplemental indenture in form and substance reasonably
                  satisfactory to the Trustee;

            (2)   immediately after giving effect to such transaction, no
                  Default or Event of Default exists; and

            (3)   such Restricted Subsidiary, or any Person formed by or
                  surviving any such consolidation or merger, would be permitted
                  to incur, immediately after giving


                                       32
<PAGE>

                  effect to such transaction, at least $1.00 of additional
                  Indebtedness pursuant to the test set forth in the first
                  paragraph of Section 4.8 of the Indenture.

In the event of:

            (1)   a sale or other disposition of all of the assets of any
                  Restricted Subsidiary, by way of merger, consolidation or
                  otherwise;

            (2)   a sale or other disposition of all of the capital stock of any
                  Restricted Subsidiary; or

            (3)   the designation of a Restricted Subsidiary as an Unrestricted
                  Subsidiary in accordance with the terms of Section 4.14 of the
                  Indenture,

then such Subsidiary (in the event of a sale or other disposition, by way of
such a merger, consolidation or otherwise, of all of the capital stock of such
Restricted Subsidiary or in the event of the designation of such Restricted
Subsidiary as an Unrestricted Subsidiary) or the Person acquiring the property
(in the event of a sale or other disposition of all of the assets of such
Restricted Subsidiary) will be released and relieved of any obligations under
its Subsidiary Guarantee, provided that the Net Proceeds of such sale or other
disposition are applied in accordance with the applicable provisions of Section
4.16 of the Indenture.

            (i) Designation of Unrestricted Subsidiaries.

            Section 4.14. Designation of Unrestricted Subsidiaries. The Board
of Directors may designate any Subsidiary (including any Restricted
Subsidiary or any newly acquired or newly formed Subsidiary) to be an
Unrestricted Subsidiary so long as:

            (1)   neither the Company nor any Restricted Subsidiary is directly
                  or indirectly liable for any Indebtedness of such Subsidiary;

            (2)   no default with respect to any Indebtedness of such Subsidiary
                  would permit (upon notice, lapse of time or otherwise) any
                  holder of any other Indebtedness of the Company or any
                  Restricted Subsidiary to declare a default on such other
                  Indebtedness or cause the payment thereof to be accelerated or
                  payable prior to its stated maturity;

            (3)   any Investment in such Subsidiary deemed to be made as a
                  result of designating such Subsidiary an Unrestricted
                  Subsidiary will not violate the provisions of Section 4.7 of
                  the Indenture;

            (4)   neither the Company nor any Restricted Subsidiary has a
                  contract, agreement, arrangement, understanding or obligation
                  of any kind, whether written or oral, with such Subsidiary
                  other than (A) those that might be obtained at the time from
                  Persons who are not Affiliates of the Company or (B)
                  administrative, tax sharing and other ordinary course
                  contracts, agreements, arrangements and understandings or
                  obligations entered into in the ordinary course of business;
                  and


                                       33
<PAGE>

            (5)   neither the Company nor any Restricted Subsidiary has any
                  obligation to subscribe for additional shares of Capital Stock
                  or other Equity Interests in such Subsidiary, or to maintain
                  or preserve such Subsidiary's financial condition or to cause
                  such Subsidiary to achieve certain levels of operating results
                  other than as permitted under Section 4.7 of the Indenture.

            Notwithstanding the foregoing, the Company may not designate as an
Unrestricted Subsidiary any Subsidiary which, on the 1999 Indenture Date, was a
Significant Subsidiary, and may not sell, transfer or otherwise dispose of any
properties or assets of any such Significant Subsidiary to an Unrestricted
Subsidiary, other than in the ordinary course of business, in each case other
than Iron Mountain Global, Inc. and its Subsidiaries (including without
limitation Iron Mountain Europe Limited and its Subsidiaries).

            The Board of Directors may designate any Unrestricted Subsidiary as
a Restricted Subsidiary; provided that such designation will be deemed to be an
incurrence of Indebtedness by a Restricted Subsidiary of any outstanding
Indebtedness of such Unrestricted Subsidiary and such designation will only be
permitted if:

            (1)   such Indebtedness is permitted under Section 4.8 of the
                  Indenture and

            (2)   no Default or Event of Default would occur as a result of such
                  designation.

            (j) Limitation on Sale and Leaseback Transactions.

            Section 4.15. Limitation on Sale and Leaseback Transactions. The
Company will not, and will not permit any Restricted Subsidiary to, enter
into any Sale and Leaseback Transaction unless:

            (1)   the consideration received in such Sale and Leaseback
                  Transaction is at least equal to the fair market value of the
                  property sold, as determined by a resolution of the Board of
                  Directors and

            (2)   the Company or such Restricted Subsidiary could incur the
                  Attributable Indebtedness in respect of such Sale and
                  Leaseback Transaction in compliance with Section 4.8 of the
                  Indenture.


                                       34
<PAGE>

            (k) Asset Sales.

            Section 4.16. Asset Sales. The Company shall not, and shall not
permit any of its Restricted Subsidiaries to:

            (1)   sell, lease, convey or otherwise dispose of any assets
                  (including by way of a Sale and Leaseback Transaction, but
                  excluding a Qualifying Sale and Leaseback Transaction) other
                  than sales of inventory in the ordinary course of business
                  (provided that the sale, lease, conveyance or other
                  disposition of all or substantially all of the assets of the
                  Company will be governed by the provisions of Section 4.17 of
                  the Indenture and/or the provisions of Section 5.1 of the
                  Indenture and not by the provisions of this Section 4.16); or

            (2)   issue or sell Equity Interests of any of its Restricted
                  Subsidiaries

that in the case of either clause (1) or (2) above, whether in a single
transaction or a series of related transactions:

            (i)   have a fair market value in excess of $2.0 million or

            (ii)  result in Net Proceeds in excess of $2.0 million (each of the
                  foregoing, an "Asset Sale"), unless (x) the Company (or the
                  Restricted Subsidiary, as the case may be) receives
                  consideration at the time of such Asset Sale at least equal to
                  the fair market value (evidenced by an Officers' Certificate
                  delivered to the Trustee, and for Asset Sales having a fair
                  market value or resulting in Net Proceeds in excess of $10.0
                  million, evidenced by a resolution of the Board of Directors
                  set forth in an Officers' Certificate delivered to the
                  Trustee) of the assets sold or otherwise disposed of and (y)
                  at least 75% of the consideration therefor received by the
                  Company or such Restricted Subsidiary is in the form of cash
                  or like-kind assets (in each case as determined in good faith
                  by the Company, evidenced by a resolution of the Board of
                  Directors and certified by an Officers' Certificate delivered
                  to the Trustee);

provided, however, that the amount of

            (A)   any liabilities (as shown on the Company's or such Restricted
                  Subsidiary's most recent balance sheet or in the notes
                  thereto) of the Company or such Restricted Subsidiary (other
                  than liabilities that are by their terms subordinated to the
                  Notes or any Subsidiary Guarantee) that are assumed by the
                  transferee of any such assets and

            (B)   any notes or other obligations received by the Company or such
                  Restricted Subsidiary from such transferee that are
                  immediately converted by the Company or such Restricted
                  Subsidiary into cash (to the extent of the cash received) or
                  Cash Equivalents,

shall be deemed to be cash for purposes of this provision; and provided,
further, that the 75% limitation referred to in the foregoing clause (ii) (y)
shall not apply to any Asset Sale in which the cash portion of


                                       35
<PAGE>

the consideration received therefrom is equal to or greater than what the
after-tax proceeds would have been had such Asset Sale complied with the
aforementioned 75% limitation.

            A transfer of assets or issuance of Equity Interests by the Company
to a Wholly Owned Restricted Subsidiary or by a Wholly Owned Restricted
Subsidiary to the Company or to another Wholly Owned Restricted Subsidiary will
not be deemed to be an Asset Sale.

            Within 360 days of any Asset Sale, the Company may, at its option,
apply an amount equal to the Net Proceeds from such Asset Sale either:

            (1)   to permanently reduce Senior Debt or

            (2)   to an investment in a Restricted Subsidiary or in another
                  business or capital expenditure or other long-term/tangible
                  assets, in each case, in the same line of business as the
                  Company or any of its Restricted Subsidiaries was engaged in
                  on the date of the First Supplemental Indenture or in
                  businesses similar or reasonably related thereto.

            Pending the final application of any such Net Proceeds, the Company
may temporarily reduce Senior Bank Debt or otherwise invest such Net Proceeds in
any manner that is not prohibited by the Indenture. Any Net Proceeds from such
Asset Sale that are not applied or invested as provided in the first sentence of
this paragraph will be deemed to constitute "Excess Proceeds." When the
aggregate amount of Excess Proceeds exceeds $10.0 million, the Company shall
make an offer to all Holders of the Notes, all holders of the 9 1/8% Notes, the
8 1/4% Notes, the 8 1/8% Notes and the 8 3/4% Notes and the holders of any
future Indebtedness ranking pari passu with the Notes, which Indebtedness
contains similar provisions requiring the Company to repurchase such
Indebtedness (an "Asset Sale Offer"), to purchase the maximum principal amount
of Notes and such other Indebtedness that may be purchased out of the Excess
Proceeds, at an offer price in cash in an amount equal to 100% of the principal
amount thereof plus accrued and unpaid interest, if any, to the date of
purchase, in accordance with the procedures set forth in the Indenture;
provided, however, that prior to making any such Asset Sale Offer, the Company
may, to the extent required by the indentures for the 10 1/8% Notes or the
11 1/8% Notes, use such Excess Proceeds to repurchase the 10 1/8% Notes and the
11 1/8% Notes. To the extent that the aggregate amount of Notes and other pari
passu Indebtedness (including the 9 1/8% Notes, the 8 1/4% Notes, the 8 1/8%
Notes and the 8 3/4% Notes) tendered pursuant to an Asset Sale Offer is less
than the Excess Proceeds, the Company may use any remaining Excess Proceeds for
general corporate purposes. If the aggregate principal amount of Notes and such
other Indebtedness surrendered by Holders thereof exceeds the amount of Excess
Proceeds, the Trustee shall select the Notes and such other Indebtedness to be
purchased on a pro rata basis. Upon completion of such offer to purchase, the
amount of Excess Proceeds shall be reset at zero.

            The Company shall comply with the requirements of Rule 14e-1 under
the Exchange Act and any other securities laws and regulations thereunder to the
extent those laws and regulations are applicable in connection with each
repurchase of Notes pursuant to an Asset Sale Offer. To the extent that the
provisions of any securities laws or regulations conflict with the provisions of
this Section 4.16 of the Indenture, the Company shall comply with the applicable
securities laws and regulations and shall not be deemed to have breached its
obligations under the Asset Sale provisions of the Indenture by virtue of such
conflict.


                                       36
<PAGE>

            An Asset Sale Offer shall be made pursuant to the provisions of
Section 3.9 hereof. No later than the date which is five Business Days after the
date on which the aggregate amount of Excess Proceeds exceeds $10.0 million, the
Company shall notify the Trustee of such Asset Sale Offer and provide the
Trustee with an Officers' Certificate setting forth the calculations used in
determining the amount of Net Proceeds to be applied to the purchase of Notes.
The Company shall commence or cause to be commenced the Asset Sale Offer on a
date no later than 15 Business Days after such notice (the "Commencement Date").

            (l)   Change of Control Offer.

            Section 4.17. Change of Control Offer.

            (a) Upon the occurrence of a Change of Control, each Holder of Notes
shall have the right to require the Company to repurchase all or any part (equal
to $1,000 or an integral multiple thereof) of such Holder's Notes pursuant to
the offer described below (the "Change of Control Offer") at an offer price in
cash equal to 101% of the aggregate principal amount thereof plus accrued and
unpaid interest to but excluding the date of repurchase (the "Change of Control
Payment").

            Within 30 calendar days following any Change of Control, the Company
shall mail a notice to each Holder stating:

            (1)   that the Change of Control Offer is being made pursuant to
                  this Section 4.17 and that all Notes tendered shall be
                  accepted for payment;

            (2)   the purchase price and the purchase date, which shall be no
                  earlier than 30 calendar days nor later than 60 calendar days
                  from the date such notice is mailed (the "Change of Control
                  Payment Date");

            (3)   that any Note not tendered shall continue to accrue interest;

            (4)   that, unless the Company defaults in the payment of the Change
                  of Control Payment, all Notes accepted for payment pursuant to
                  the Change of Control Offer shall cease to accrue interest on
                  and after the Change of Control Payment Date;

            (5)   that Holders electing to have any Notes purchased pursuant to
                  a Change of Control Offer shall be required to surrender the
                  Notes, with the form entitled "Option of Holder to Elect
                  Purchase" on the reverse of the Notes completed, to the paying
                  agent at the address specified in such notice prior to the
                  close of business on the fifth Business Day preceding the
                  Change of Control Payment Date;

            (6)   that Holders will be entitled to withdraw their election if
                  the Paying Agent receives, not later than the close of
                  business on the second Business Day preceding the Change of
                  Control Payment Date, facsimile transmission or letter setting
                  forth the name of the Holder, the principal amount of Notes
                  delivered for purchase, and a statement that such Holder is
                  withdrawing its election to have such Notes purchased; and


                                       37
<PAGE>

            (7)   that Holders whose Notes are being purchased only in part will
                  be issued new Notes equal in principal amount to the
                  unpurchased portion of the Notes surrendered, which
                  unpurchased portion must be equal to $1,000 in principal
                  amount or an integral multiple thereof.

            The Company shall comply with the requirements of Rule 14e-1 under
the Exchange Act and any other securities laws and regulations thereunder to the
extent such laws and regulations are applicable to the repurchase of the Notes
in connection with a Change of Control. To the extent that the provisions of any
securities laws or regulations conflict with this Section 4.17, the Company
shall comply with the applicable securities laws and regulations and shall not
be deemed to have breached its obligations under the Indenture or the First
Supplemental Indenture by virtue of such conflict.

            (b) On the Change of Control Payment Date, the Company shall, to the
extent lawful:

            (1)   accept for payment Notes or portions thereof tendered pursuant
                  to the Change of Control Offer;

            (2)   deposit with the Paying Agent an amount equal to the Change of
                  Control Payment in respect of all Notes or portions thereof so
                  tendered; and

            (3)   deliver or cause to be delivered to the Trustee the Notes so
                  accepted together with an Officers' Certificate stating the
                  Notes or portions thereof tendered to the Company.

            The Paying Agent shall promptly mail to each Holder of Notes so
accepted the Change of Control Payment for such Notes, and the Trustee shall
promptly authenticate and mail to each Holder a new Note equal in principal
amount to any unpurchased portion of the Notes surrendered, if any; provided
that each such new Note shall be in a principal amount of $1,000 or an integral
multiple thereof. Prior to complying with the provisions of this Section 4.17,
but in any event within 90 calendar days following a Change of Control, the
Company shall either repay all outstanding Senior Debt or obtain the requisite
consents, if any, under all agreements governing outstanding Senior Debt to
permit the repurchase of Notes required by this Section 4.17. The Company shall
publicly announce in The Wall Street Journal, or if no longer published, a
national newspaper of general circulation, the results of the Change of Control
Offer on or as soon as practicable after the Change of Control Payment Date.

            The Company shall not be required to make a Change of Control Offer
upon a Change of Control if a third party makes the Change of Control Offer in
the manner, at the times and otherwise in compliance with the requirements set
forth in this Section 4.17 applicable to a Change of Control Offer made by the
Company and purchases all Notes properly tendered and not withdrawn under the
Change of Control Offer.

            (m) Corporate Existence.

            With respect to the Notes issued under this First Supplemental
Indenture, Section 4.5 of the Indenture is replaced in its entirety as follows:


                                       38
<PAGE>

            Section 4.5. Corporate Existence.

            Subject to Section 4.13 and Article V of the Indenture, as the case
may be, the Company and each of the Restricted Subsidiaries shall do or cause to
be done all things necessary to preserve and keep in full force and effect (i)
its corporate existence, and the corporate, partnership or other existence of
each of their Subsidiaries, in accordance with the respective organizational
documents (as the same may be amended from time to time) of the Company, any
such Restricted Subsidiary or any such Subsidiary, as the case may be, and (ii)
the rights (charter and statutory), licenses and franchises of the Company, the
Restricted Subsidiaries and their respective Subsidiaries; provided, however,
that the Company and the Restricted Subsidiaries shall not be required to
preserve any such right, license or franchise, or the corporate, partnership or
other existence of any of their respective Subsidiaries, if an officer of the
Company shall determine that the preservation thereof is no longer desirable in
the conduct of the business of the Company, the Restricted Subsidiaries and
their Subsidiaries, taken as a whole, and that the loss thereof is not adverse
in any material respect to the Holders of the Notes.

Section 2.7. Mergers, Consolidations or Sale of Assets.

            With respect to the Notes issued under this First Supplemental
Indenture, Section 5.1 of the Indenture is replaced in its entirety as follows:

            Section 5.1. Mergers, Consolidations or Sale of Assets.

            The Company may not consolidate or merge with or into (whether or
not the Company is the surviving corporation), or sell, assign, transfer, lease,
convey or otherwise dispose of all or substantially all of its properties or
assets in one or more related transactions, to another Person unless:

            (1)   the Company is the surviving corporation or the Person formed
                  by or surviving any such consolidation or merger (if other
                  than the Company) or to which such sale, assignment, transfer,
                  lease, conveyance or other disposition shall have been made is
                  a corporation organized or existing under the laws of the
                  United States, any state thereof or the District of Columbia;

            (2)   the Person formed by or surviving any such consolidation or
                  merger (if other than the Company) or the Person to which such
                  sale, assignment, transfer, lease, conveyance or other
                  disposition shall have been made assumes all the obligations
                  of the Company under the Notes, the First Supplemental
                  Indenture and the Indenture (pursuant to a supplemental
                  indenture in a form reasonably satisfactory to the Trustee);

            (3)   immediately after such transaction no Default or Event of
                  Default exists; and

            (4)   the Company or any Person formed by or surviving any such
                  consolidation or merger, or to which such sale, assignment,
                  transfer, lease, conveyance or other disposition shall have
                  been made, will, at the time of such transaction and after
                  giving pro forma effect thereto, be permitted to incur at
                  least $1.00 of additional Indebtedness pursuant to the test
                  set forth in the first paragraph of Section 4.8 of the
                  Indenture.


                                       39
<PAGE>

Section 2.8. Events of Default.

            With respect to the Notes issued under this First Supplemental
Indenture, Section 6.1 of the Indenture is hereby replaced in its entirety as
follows:

            Section 6.1. Events of Default.

            Each of the following constitutes an "Event of Default:"

            (1)   default for 30 days in the payment when due of interest on the
                  Notes (whether or not prohibited by the subordination
                  provisions of Article XIII of the Indenture);

            (2)   default in payment when due of the principal of or premium, if
                  any, on the Notes (whether or not prohibited by the
                  subordination provisions in Article XIII of the Indenture);

            (3)   failure by the Company to comply with Section 4.17 of the
                  Indenture;

            (4)   failure by the Company or any Guarantor for 60 days after
                  written notice from the Trustee or Holders of not less than
                  25% of the aggregate principal amount of the Notes (including
                  the Additional Notes, if any) then outstanding to comply with
                  any of its other agreements in the Indenture, the First
                  Supplemental Indenture, the Notes or the Subsidiary Guarantees
                  (in order to be effective, such notice must be in writing,
                  specify the Default, demand that it be remedied and state that
                  the notice is a "Notice of Default");

            (5)   default under any mortgage, indenture or instrument under
                  which there may be issued or by which there may be secured or
                  evidenced any Indebtedness for money borrowed by the Company
                  or any of its Restricted Subsidiaries (or the payment of which
                  is guaranteed by the Company or any of its Restricted
                  Subsidiaries) whether such Indebtedness or guarantee exists on
                  the date of the First Supplemental Indenture or is created
                  thereafter, if:

                  (i)   such default results in the acceleration of such
                        Indebtedness prior to its express maturity or shall
                        constitute a default in the payment of such Indebtedness
                        at final maturity of such Indebtedness and

                  (ii)  the principal amount of any such Indebtedness that has
                        been accelerated or not paid at maturity, when added to
                        the aggregate principal amount of all other such
                        Indebtedness that has been accelerated or not paid at
                        maturity, exceeds $10.0 million;

            (6)   a final judgment or final judgments for the payment of money
                  are entered by a court or courts of competent jurisdiction
                  against the Company or any of its Restricted Subsidiaries and
                  such judgments remain unpaid, undischarged or unstayed for a
                  period of 60 days, provided that the aggregate of all such
                  unpaid, undischaraged or unstayed judgments exceeds $10.0
                  million;


                                       40
<PAGE>

            (7)   the Company or any of its Restricted Subsidiaries that is a
                  Significant Subsidiary:

                  (i)   commences a voluntary case,

                  (ii)  consents to the entry of an order for relief against it
                        in an involuntary case,

                  (iii) consents to the appointment of a Custodian of it or for
                        all or substantially all of its property,

                  (iv)  makes a general assignment for the benefit of its
                        creditors, or

                  (v)   admits in writing that it generally is unable to pay its
                        debts as the same become due;

                  in each case, pursuant to or within the meaning of any
                  Bankruptcy Law; or

            (8)   a court of competent jurisdiction enters an order or decree
                  under any Bankruptcy Law that:

                  (i)   is for relief against the Company or any of its
                        Restricted Subsidiaries that is a Significant Subsidiary
                        in an involuntary case,

                  (ii)  appoints a Custodian of the Company or any of its
                        Restricted Subsidiaries that is a Significant Subsidiary
                        or for all or substantially all of its property, or

                  (iii) orders the liquidation of the Company or any of its
                        Restricted Subsidiaries that is a Significant
                        Subsidiary,

                  and such order or decree remains unstayed and in effect for 60
                  days; or

            (9)   except as permitted by the Indenture, the First Supplemental
                  Indenture or the Subsidiary Guarantees, any Subsidiary
                  Guarantee issued by a Restricted Subsidiary shall be held in
                  any judicial proceeding to be unenforceable or invalid or
                  shall cease for any reason to be in full force and effect, or
                  any Restricted Subsidiary or any Person acting on behalf of
                  any Restricted Subsidiary shall deny or disaffirm in writing
                  its obligations under its Subsidiary Guarantee.

The term "Bankruptcy Law" means title 11, U.S. Code or any similar Federal or
State law for the relief of debtors. The term "Custodian" means any receiver,
trustee, assignee, liquidator or similar official under any Bankruptcy Law.

Section 2.9. Acceleration.

            With respect to the Notes issued under this First Supplemental
Indenture, Section 6.2 of the Indenture is hereby replaced in its entirety as
follows:


                                       41
<PAGE>

            Section 6.2. Acceleration of Maturity.

            If any Event of Default (other than an Event of Default specified in
clauses (7)(i) through (7)(v) and (8) of Section 6.1 of the Indenture relating
to the Company or any of its Restricted Subsidiaries that is a Significant
Subsidiary) occurs and is continuing, the Trustee by notice to the Company or
the Holders of at least 25% in principal amount of the then outstanding Notes by
notice to the Company and the Trustee may declare the unpaid principal of and
any interest on all the Notes to be due and payable immediately; provided,
however, that if any Obligation with respect to Senior Bank Debt is outstanding
pursuant to the Credit Agreement upon a declaration of acceleration of the
Notes, the principal, premium, if any, and interest on the Notes will not be
payable until the earlier of:

            (1)   the day which is five Business Days after written notice of
                  acceleration is received by the Company and the Credit Agent
                  or

            (2)   the date of acceleration of the Indebtedness under the Credit
                  Agreement. If an Event of Default specified in clauses (7)(i)
                  through (7)(v) and (8) of Section 6.1 of the Indenture with
                  respect to the Company or any Restricted Subsidiary that is a
                  Significant Subsidiary occurs, the principal of, and premium,
                  if any, and any accrued and unpaid interest on all outstanding
                  Notes will become immediately due and payable without further
                  action or notice.

            In the event of a declaration of acceleration of the Notes because
an Event of Default has occurred and is continuing as a result of the
acceleration of any Indebtedness described in clause (5) of Section 6.1 of the
Indenture, the declaration of acceleration of the Notes shall be automatically
annulled if the holders of any Indebtedness described in such clause have
rescinded the declaration of acceleration in respect of such Indebtedness within
30 days from the date of such declaration and if:

            (1)   the annulment of the acceleration of the Notes would not
                  conflict with any judgment or decree of a competent
                  jurisdiction and

            (2)   all existing Events of Default, except non-payment of
                  principal or interest on the Notes that became due solely
                  because of the acceleration of the Notes, have been cured or
                  waived.

            In the case of any Event of Default occurring by reason of any
willful action (or inaction) taken (or not taken) by or on behalf of the Company
with the intention of avoiding payment of the Make Whole Price or premium, as
applicable, that the Company would have had to pay if the Company then had
elected to redeem the Notes pursuant to the optional redemption provisions of
the Indenture, the applicable Make Whole Price, or an equivalent premium, as the
case may be, shall become and be immediately due and payable to the extent
permitted by law upon the acceleration of the Notes.

Section 2.10. Amendments and Waivers.

            With respect to the Notes issued under this First Supplemental
Indenture, the following Sections replace in their entirety Sections 9.1, 9.2,
9.3 and 9.5 of the Indenture:


                                       42
<PAGE>

            Section 9.1. Without Consent of Holders.

            Notwithstanding Section 9.2 of the Indenture, without the consent of
any Holder of Notes, the Company, the Guarantors and the Trustee may amend or
supplement the Indenture or the Notes:

            (a)   to cure any ambiguity, defect or inconsistency,

            (b)   to provide for uncertificated Notes in addition to or in place
                  of certificated Notes,

            (c)   to provide for the assumption of the Company's or any
                  Guarantor's obligations to Holders of the Notes in the case of
                  a merger or consolidation,

            (d)   to make any change that would provide any additional rights or
                  benefits to the Holders of the Notes (including providing for
                  additional Subsidiary Guarantees pursuant to Section 4.13 of
                  the Indenture) or that does not materially adversely affect
                  the legal rights under the Indenture of any such Holder, or

            (e)   to comply with requirements of the SEC in order to effect or
                  maintain the qualification of the Indenture under the TIA.

            Upon the request of the Company accompanied by a resolution of its
Board of Directors authorizing the execution of any such amended or supplemental
Indenture, and upon receipt by the Trustee of the documents described in Section
7.2 of the Indenture, the Trustee shall join with the Company and the Guarantors
in the execution of any amended or supplemental Indenture authorized or
permitted by the terms of this Indenture and to make any further appropriate
agreements and stipulations that may be therein contained, but the Trustee shall
not be obligated to enter into such amended or supplemental Indenture that
affects its own rights, duties or immunities under this Indenture or otherwise.

            Section 9.2. With Consent of Holders.

            Except as provided Section 9.1 and Section 9.3 of the Indenture, the
Indenture or the Notes may be amended or supplemented with the consent of the
Holders of at least a majority in principal amount of the Notes then outstanding
(including consents obtained in connection with a tender offer or exchange offer
for Notes), and, subject to Sections 6.8 and 6.12 of the Indenture) any existing
Default or Event of Default (other than a Default or Event of Default in the
payment of the principal of, premium, if any, or interest on the Notes, except a
payment default resulting from an acceleration that has been rescinded) or
compliance with any provision of the Indenture or the Notes may be waived with
the consent of the Holders of a majority in principal amount of the then
outstanding Notes (including consents obtained in connection with a tender offer
or exchange offer for Notes).

            It shall not be necessary for the consent of the Holders of Notes
under this Section 9.2 to approve the particular form of any proposed amendment
or waiver, but it shall be sufficient if such consent approves the substance
thereof.

            Upon the request of the Company accompanied by a resolution of its
Board of Directors authorizing the execution of any such amended or supplemental
Indenture, and upon the filing with the Trustee of evidence reasonably
satisfactory to the Trustee of the consent of the Holders of Notes as


                                       43
<PAGE>

aforesaid, and upon receipt by the Trustee of the documents described in Section
7.2 hereof, the Trustee shall join with the Company and the Guarantors in the
execution of such amended or supplemental Indenture unless such amended or
supplemental Indenture affects the Trustee's own rights, duties or immunities
under this Indenture or otherwise, in which case the Trustee may in its
discretion, but shall not be obligated to, enter into such amended or
supplemental Indenture.

            Section 9.3. Limitations.

            Without the consent of each Holder affected, an amendment or waiver
may not (with respect to any Notes held by a non-consenting Holder of Notes):

            (1)   reduce the principal amount of Notes whose Holders must
                  consent to an amendment, supplement or waiver;

            (2)   reduce the principal of or change the fixed maturity of any
                  Note or alter any of the provisions with respect to the
                  redemption of the Notes in a manner adverse to the Holders of
                  the Notes;

            (3)   reduce the rate of or change the time for payment of interest
                  on any Note;

            (4)   waive a Default or Event of Default in the payment of
                  principal of or premium, if any, or interest on the Notes
                  (except a rescission of acceleration of the Notes by the
                  Holders of at least a majority in aggregate principal amount
                  of the then outstanding Notes and a waiver of the payment
                  default that resulted from such acceleration);

            (5)   make any Note payable in money other than that stated in the
                  Notes;

            (6)   make any change in the provisions of the Indenture relating to
                  waivers of past Defaults or the rights of Holders of Notes to
                  receive payments of principal of or premium, if any, or
                  interest on the Notes;

            (7)   waive a redemption payment with respect to any Note (other
                  than a payment required by Section 4.16 and Section 4.17 of
                  the Indenture);

            (8)   except pursuant to the Indenture, release any Guarantor from
                  its obligations under its Subsidiary Guarantee, or change any
                  Subsidiary Guarantee in any manner that would materially
                  adversely affect the Holders; or

            (9)   make any change in the foregoing amendment and waiver
                  provisions.

            It shall not be necessary for the consent of the Holders of Notes
under this Section 9.3 to approve the particular form of any proposed amendment
or waiver, but it shall be sufficient if such consent approves the substance
thereof.

            Section 9.5. Revocation and Effect of Consents.


                                       44
<PAGE>

            Until an amendment or waiver becomes effective, a consent to it by a
Holder of a Note is a continuing consent by the Holder and every subsequent
Holder of a Note or portion of a Note that evidences the same debt as the
consenting Holder's Note, even if notation of the consent is not made on any
Note. However, any such Holder or subsequent Holder may revoke the consent as to
his Note or portion of a Note if the Trustee receives the notice of revocation
before the date the amendment or waiver becomes effective.

            Any amendment or waiver once effective shall bind every Holder
unless it is of the type described in any of clauses (1) through (8) of Section
9.3. In that case, the amendment or waiver shall bind each Holder who has
consented to it and every subsequent Holder of a Note or portion of a Note that
evidences the same debt as the consenting Holder's Note.

Section 2.11. Subsidiary Guarantees.

            With respect to the Notes issued under this Supplemental Indenture,
Article XII of the Indenture shall apply, and the Notes shall constitute a
Series to be guaranteed by the Guarantors pursuant to Article XII of the
Indenture.

Section 2.12. Legal Defeasance and Covenant Defeasance.

            With respect to the Notes issued under this Supplemental Indenture,
Article VIII of the Indenture shall apply, and the Company shall have the option
to effect Legal Defeasance or Covenant Defeasance pursuant to Article VIII of
the Indenture. In connection with any Covenant Defeasance, the Company shall be
released from its obligations under the covenants specified in Sections 2.6 and
2.7 of this First Supplemental Indenture.

Section 2.13. Subordination.

            (a) With respect to the Notes issued under this Supplemental
Indenture, Article XIII of the Indenture shall apply, and the Notes shall be
subject to subordination pursuant to Article XIII of the Indenture. In addition,
with respect to the Notes issued under this First Supplemental Indenture, the
following Sections shall be added to Article XIII of the Indenture.

            (b) Guarantors May Consolidate, etc., on Certain Terms.

            Section 13.27. Guarantors May Consolidate, etc., on Certain Terms.

            No Guarantor shall consolidate with or merge with or into (whether
or not such Guarantor is the surviving Person), another Person whether or not it
is affiliated with such Guarantor unless (i) subject to the provisions of
Section 11.28 hereof, the Person formed by or surviving any such consolidation
or merger (if other than a Guarantor) assumes all the obligations of such
Guarantor pursuant to a supplemental indenture in form reasonably satisfactory
to the Trustee, under its Subsidiary Guarantee, the Notes and this Indenture,
(ii) immediately after giving effect to such transaction, no Default or Event of
Default exists, and (iii) such Guarantor, or any person formed by or surviving
any such consolidation or merger, will be permitted to incur, immediately after
giving effect to such transaction, at least $1.00 of additional Indebtedness
pursuant to the first paragraph of Section 4.8 hereof. In case of any such
consolidation, merger, sale or conveyance and upon the assumption by the
successor


                                       45
<PAGE>

Person, by supplemental indenture, executed and delivered to the Trustee and
satisfactory in form to the Trustee, of the Subsidiary Guarantee in this
Indenture and the due and punctual performance and observance of all of the
covenants and conditions of this Indenture to be performed by the Guarantor,
such successor Person shall succeed to and be substituted for the Guarantor with
the same effect as if it had been named herein as a Guarantor.

            (c) Releases Following Sale of Assets or Designation as Unrestricted
Subsidiary.

            Section 13.28. Releases Following Sale of Assets or Designation as
                      Unrestricted Subsidiary.

            In the event of (a) a sale or other disposition of all or
substantially all of the assets of any Guarantor, by way of merger,
consolidation or otherwise, or (b) a sale or other disposition of all of the
capital stock of any Guarantor, or (c) the designation of a Restricted
Subsidiary as an Unrestricted Subsidiary in accordance with the terms of Section
4.14 hereof, then such Guarantor (in the event of a sale or other disposition,
by way of such a merger, consolidation or otherwise, of all of the capital stock
of such Guarantor, or in the event of the designation of such Guarantor as an
Unrestricted Subsidiary) or the Person acquiring the property (in the event of a
sale or other disposition of all or substantially all of the assets of such
Guarantor) shall be released and relieved of its obligations under its
Subsidiary Guarantee; provided that the Net Proceeds of such sale or other
disposition are applied in accordance with Section 4.16 hereof.

                                   ARTICLE 3.

                                  MISCELLANEOUS

Section 3.1. Effect of Headings.

            The Article and Section headings herein are for convenience only and
shall not affect the construction hereof.

Section 3.2. Successors and Assigns.

            All covenants and agreements in this First Supplemental Indenture by
the Company shall bind its successors and assigns, whether so expressed or not.


                                       46
<PAGE>

Section 3.3. Separability Clause.

            In case any provision in this First Supplemental Indenture or in the
Notes shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

Section 3.4. Governing Law.

            This First Supplemental Indenture and the Notes created hereby shall
be governed by and construed in accordance with the laws of the State of New
York without giving effect to any conflicts of law provisions (other than
Section 5-1401 of the New York General Obligations Law) that might cause this
First Supplemental Indenture and the Notes to be governed by or construed or
enforced in accordance with the laws of any other jurisdiction.

Section 3.5. First Supplement to Supersede Indenture.

            The Indenture, as supplemented by the First Supplemental Indenture,
remains in full force and effect as of the date hereof. Notwithstanding the
foregoing, to the extent that any provision of the Indenture shall conflict with
any provision of this First Supplemental Indenture, the terms of this First
Supplemental Indenture shall be deemed controlling and the conflicting provision
of the Indenture shall be null and void to the extent of such conflict.

           [The rest of this page has been intentionally left blank.]


                                       47
<PAGE>

            IN WITNESS WHEREOF, the parties have caused this First Supplemental
Indenture to be duly executed, and attested, all as of the date and year first
written above.

                             IRON MOUNTAIN INCORPORATED

                             By: /s/ C. Richard Reese
                                 -----------------------------------------------
                                 Name: C. Richard Reese
                                 Title: Chairman and Chief Executive Officer


                             ARCUS DATA SECURITY, INC.
                             COMAC, INC.
                             DSI TECHNOLOGY ESCROW SERVICES, INC.
                             IM BILLERICA, INC.
                             IRON MOUNTAIN GLOBAL, INC.
                             IRON MOUNTAIN RECORDS MANAGEMENT, INC.
                             IRON MOUNTAIN RECORDS MANAGEMENT OF MICHIGAN, INC.

                             By: /s/ C. Richard Reese
                                 -----------------------------------------------
                                 Name: C. Richard Reese
                                 Title: Chairman and Chief Executive Officer


                             IRON MOUNTAIN/NATIONAL UNDERGROUND STORAGE, LLC
                             IRON MOUNTAIN CONSULTING SERVICES, LLC
                             IRON MOUNTAIN CONFIDENTIAL DESTRUCTION LLC

                             By: Iron Mountain Records Management, Inc.,
                                 its sole Member

                                 By: /s/ C. Richard Reese
                                     -------------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman and Chief Executive Officer

                           [Indenture Signature Page]

<PAGE>

                             IRON MOUNTAIN GLOBAL LLC

                             By: Iron Mountain Global, Inc., its sole Member

                                 By: /s/ C. Richard Reese
                                     -------------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman and Chief Executive Officer


                             ARCUS DATA SECURITY LLC

                             By: Arcus Data Security, Inc., its sole Member

                                 By: /s/ C. Richard Reese
                                     -------------------------------------------
                                     Name: C. Richard Reese
                                     Title: Chairman and Chief Executive Officer


                             THE BANK OF NEW YORK, as Trustee

                             By: /s/ Kisha A. Holder
                                 -----------------------------------------------
                                 Name: Kisha A. Holder
                                 Title: Assistant Treasurer

                  [First Supplemental Indenture Signature Page]

<PAGE>

                                                                       Exhibit A

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

                                 [Face of Note]
                    8 5/8% Senior Subordinated Notes due 2013

No. ___________________                                         $_______________

                           IRON MOUNTAIN INCORPORATED

promises to pay to _____________ or registered assigns, the principal sum of
___________________ Dollars on April 1, 2013.

            Interest Payment Dates: April 1 and October 1

            Record Dates: March 15 and September 15

            Dated: April [ ], 2001

            CUSIP No. ________________

                                                IRON MOUNTAIN INCORPORATED


                                                By:   __________________________
                                                Name:
                                                Title:


                                                By:   __________________________
                                                Name:
                                                Title:

                                     (SEAL)

This is one of the Notes
referred to in the within-
mentioned Indenture:

THE BANK OF NEW YORK,
as Trustee


By: __________________________
       Authorized Signature

<PAGE>

                                 [Back of Note]
                    8 5/8% Senior Subordinated Notes due 2013

            [INSERT IN GLOBAL NOTES] [This Security is a Global Security within
the meaning of the Indenture hereinafter referred to and is registered in the
name of the Depository or a nominee of the Depository. This Security is
exchangeable for Securities registered in the name of a person other than the
Depository or its nominee only in the limited circumstances described in the
Indenture, and may not be transferred except as a whole by the Depository to a
nominee of the Depository, by a nominee of the Depository to the Depository or
another nominee of the Depository or by the Depository or any such nominee to a
successor Depository or a nominee of such a successor Depository.]

            Unless and until it is exchanged in whole or in part for Notes in
definitive form, this Note may not be transferred except as a whole by the
Depository to a nominee of the Depository or by a nominee of the Depository to
the Depository or another nominee of the Depository or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository. Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) ("DTC"),
to the issuer or its agent for registration of transfer, exchange or payment,
and any certificate issued is registered in the name of Cede & Co. or such other
name as may be requested by an authorized representative of DTC (and any payment
is made to Cede & Co. or such other entity as may be requested by an authorized
representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner
hereof, Cede & Co., has an interest herein.

            Capitalized terms used herein shall have the meanings assigned to
them in the Indenture referred to below unless otherwise indicated.

            1. INTEREST. Iron Mountain Incorporated, a Pennsylvania corporation
(the "Company") promises to pay interest on the principal amount of this Note at
8 5/8% per annum from April [ ], 2001 until April 1, 2013. The Company shall pay
interest, semi-annually in arrears on April 1 and October 1 of each year, or if
any such day is not a Business Day, on the next succeeding Business Day (each an
"Interest Payment Date"). Interest on the Notes will accrue from the most recent
date to which interest has been paid or, if no interest has been paid, from the
date of issuance; provided that if there is no existing Default in the payment
of interest, and if this Note is authenticated between a record date referred to
on the face hereof and the next succeeding Interest Payment Date, interest shall
accrue from such next succeeding Interest Payment Date; provided, further, that
the first Interest Payment Date shall be October 1, 2001. The Company shall pay
interest (including post-petition interest to the extent allowed in any
proceeding under any Bankruptcy Law) on overdue principal from time to time on
demand at a rate equal to the per annum rate on the Notes then in effect; it
shall pay interest (including post-petition interest to the extent allowed in
any proceeding under any Bankruptcy Law) on overdue installments of interest
(without regard to any applicable grace periods) from time to time on demand at
the same rate to the extent lawful. Interest will be computed on the basis of a
360-day year of twelve 30-day months.

            2. METHOD OF PAYMENT. The Company will pay principal and interest in
money of the United States that at the time of payment is legal tender for
payment of public and private debts. The Company, however, may pay principal,
premium, if any, and interest by check payable in such money. It may mail an
interest check to a Holder's registered address.

<PAGE>

            3. PAYING AGENT, REGISTRAR AND SERVICE AGENT. Initially, The Bank of
New York, the Trustee under the Indenture, will act as Paying Agent, Registrar
and Service Agent. The Notes may be presented for registration of transfer and
exchange at the offices of the Registrar. The Company may change any Paying
Agent, Service Agent or Registrar without notice to any Holder. The Company or
any of its Subsidiaries may act in any such capacity.

            4. INDENTURE. The Company issued the Notes under an Indenture
dated as of April 3, 2001 (the "Base Indenture") as supplemented by a First
Supplemental Indenture dated as of April 3, 2001 (the "Supplemental
Indenture" and, together with the Base Indenture, the "Indenture") among the
Company, the Guarantors and the Trustee. The terms of the Notes include those
stated in the Indenture and those made part of the Indenture by reference to
the Trust Indenture Act of 1939, as amended (15 U.S. Code Sections
77aaa-77bbbb). The Notes are subject to all such terms, and Holders are
referred to the Indenture and such Act for a statement of such terms. The
terms of the Indenture shall govern any inconsistencies between the Indenture
and the Notes. The Notes issued under the Indenture are subordinated
unsecured obligations of the Company limited to $500,000,000 in aggregate
principal amount.

            5. OPTIONAL REDEMPTION.

            Prior to April 1, 2006, the Notes will be subject to redemption at
any time at the option of the Company, in whole or in part, upon not less than
30 nor more than 60 days' notice, at the Make-Whole Price, plus accrued and
unpaid interest thereon to the applicable redemption date. At any time on or
after April 1, 2006, the Company may redeem any portion of the Notes, in whole
or in part, on at least 30 days, but no more than 60 days' notice at the
following prices (expressed as a percentage of the principal amount), together
with accrued and unpaid interest to, but excluding, the redemption date:

                  Redemption Period                             Redemption Price
                  -----------------                             ----------------

April 1, 2006 to March 31, 2007.............................        104.313%
April 1, 2007 to March 31, 2008.............................        102.875%
April 1, 2008 to March 31, 2009                                     101.438%
April 1, 2009 and thereafter................................        100.000%

            Notwithstanding the foregoing, at any time prior to April 1, 2004,
the Company may redeem up to 35% of the initial principal amount of the Notes
originally issued with the net proceeds of one or more Qualified Equity
Offerings at a redemption price equal to 108.625% of the principal amount of
such Notes, plus accrued and unpaid interest to the date of redemption;
provided, that at least 65% of the principal amount of Notes originally issued
remains outstanding immediately after the occurrence of any such redemption and
that such redemption occurs within 60 days following the closing of any such
Qualified Equity Offering.

            6. NOTICE OF REDEMPTION.

            Notice of redemption will be mailed at least 30 days but not more
than 60 days before the redemption date to each Holder of the Notes to be
redeemed at such Holder's address of record. The Notes in denominations larger
than $1,000 may be redeemed in part but only in integral multiples of $1,000,
unless all the Notes held by a Holder are to be redeemed. In the event of a
redemption of less than all of the Notes, the Notes will be chosen for
redemption by the Trustee in accordance with the

<PAGE>

Indenture. On and after the redemption date, interest ceases to accrue on the
Notes or portions of them called for redemption.

            If this Note is redeemed subsequent to a Record Date with respect to
any Interest Payment Date specified above and on or prior to such Interest
Payment Date, then any accrued interest will be paid to the Person in whose name
this Note is registered at the close of business on such Record Date.

            7. MANDATORY REDEMPTION. Except as set forth in paragraph 8 below,
the Company shall not be required to make mandatory redemption payments with
respect to the Notes. There are no sinking fund payments with respect to the
Notes.

            8. REPURCHASE AT OPTION OF HOLDER. This Note is subject to purchase
at the option of the Holder upon the circumstances set forth in Sections 3.9,
4.16 and 4.17 of the Indenture.

            9. SUBORDINATION. The payment of the principal of, interest on or
any other amounts due on the Notes is subordinated in right of payment to all
existing and future Senior Debt of the Company, as described in the Indenture.
Each Holder, by accepting a Note, agrees to such subordination and authorizes
and directs the Trustee on its behalf to take such action as may be necessary or
appropriate to effectuate the subordination so provided and appoints the Trustee
as its attorney-in-fact for such purpose.

            10. DENOMINATIONS, TRANSFER, EXCHANGE. The Notes are in registered
form without coupons in minimum denominations of $1,000 and integral multiples
of $1,000 in excess thereof. The transfer of Notes may be registered and Notes
may be exchanged as provided in the Indenture.

            11. PERSONS DEEMED OWNERS. Prior to due presentment to the Trustee
for registration of the transfer of this Note, the Trustee, any Agent, the
Company and the Guarantors may deem and treat the Person in whose name this Note
is registered as its absolute owner for the purpose of receiving payment of
principal of, premium, if any, and interest on this Note and for all other
purposes whatsoever, whether or not this Note is overdue, and none of the
Trustee, any Agent, the Company or any Guarantor shall be affected by notice to
the contrary. The registered Holder of a Note may be treated as its owner for
all purposes.

            12. AMENDMENT, SUPPLEMENT AND WAIVER. Subject to certain exceptions,
the Indenture with respect to the Notes or the Notes may be amended or
supplemented with the written consent of the Holders of a majority in principal
amount of the then outstanding Notes, and any existing default or compliance
with any provision of the Indenture with respect to the Notes or the Notes may
be waived with the consent of the Holders of a majority in principal amount of
the Notes (including, in each case, Additional Notes, if any). Without the
consent of any Holder of the Notes, the Indenture with respect to the Notes or
the Notes may be amended or supplemented to, in addition to other events more
fully described in the Indenture, cure any ambiguity, defect or inconsistency,
provide for uncertificated Notes in addition to or in place of certificated
Notes, provide for the assumption of the Company's or a Guarantor's obligations
to Holders of the Notes in the case of a merger or consolidation, make any
change that would provide any additional rights or benefits to the Holders of
the Notes or that does not materially adversely affect the legal rights under
the Indenture of any such Holder, or comply with requirements of the SEC in
order to effect or maintain the qualification of the Indenture under the TIA.

            13. DEFAULTS AND REMEDIES. An Event of Default with respect to the
Notes includes: the default for 30 days in the payment when due of interest on
the Notes (whether or not prohibited by the subordination provisions of the
Indenture); the default in payment when due of the principal of or premium, if
any, on the Notes (whether or not

<PAGE>

prohibited by the subordination provisions of the Indenture); the failure by the
Company to comply with Section 4.17 of the Indenture; the failure by the Company
or any Guarantor for 60 days after written notice from the Trustee or Holders of
not less than 25% of the aggregate principal amount of the Notes (including
Additional Notes, if any) outstanding to comply with any of its other agreements
in the Indenture, Notes or the Subsidiary Guarantees; the default under any
mortgage, indenture or instrument under which there may be issued or by which
there may be secured or evidenced any Indebtedness for money borrowed by the
Company or any of its Restricted Subsidiaries (or the payment of which is
guaranteed by the Company or any of its Restricted Subsidiaries) whether such
Indebtedness or guarantee exists on the date of the Indenture or is created
thereafter, if: (i) such default results in the acceleration of such
Indebtedness prior to its express maturity or shall constitute a default in the
payment of such Indebtedness at final maturity of such Indebtedness and (ii) the
principal amount of any such Indebtedness that has been accelerated or not paid
at maturity, when added to the aggregate principal amount of all other such
Indebtedness that has been accelerated or not paid at maturity, exceeds $10.0
million; the failure by the Company or any of its Restricted Subsidiaries to pay
final judgments aggregating in excess of $10.0 million, which judgments remain
unpaid, undischarged or unstayed for a period of 60 days; certain events of
bankruptcy or insolvency with respect to the Company or any of its Restricted
Subsidiaries that is a Significant Subsidiary; or except as permitted by the
Indenture or the Subsidiary Guarantees, any Subsidiary Guarantee issued by a
Restricted Subsidiary shall be held in any judicial proceeding to be
unenforceable or invalid or shall cease for any reason to be in full force and
effect, or any Restricted Subsidiary or any Person acting on behalf of any
Restricted Subsidiary shall deny or disaffirm in writing its obligations under
its Subsidiary Guarantee.

            If any Event of Default occurs and is continuing, the Trustee or the
Holders of at least 25% in principal amount of the then outstanding Notes
(including Additional Notes, if any) may declare all the Notes to be due and
payable immediately; provided, however, that if any Obligation with respect to
Senior Bank Debt is outstanding pursuant to the Credit Agreement upon a
declaration of acceleration of the Notes, the principal, premium, if any, and
interest on the Notes will not be payable until the earlier of: (1) the day
which is five business days after written notice of acceleration is received by
the Company and the Credit Agent or (2) the date of acceleration of the
Indebtedness under the Credit Agreement. Notwithstanding the foregoing, in the
case of an Event of Default arising from certain events of bankruptcy or
insolvency with respect to the Company or any Restricted Subsidiary that is a
Significant Subsidiary, the principal of, and premium, if any, and any accrued
and unpaid interest on all outstanding Notes will become due and payable without
further action or notice. In the event of a declaration of acceleration of the
Notes because an Event of Default has occurred and is continuing as a result of
the acceleration of any Indebtedness described in Section 6.1(5) of the
Indenture, the declaration of acceleration of the Notes shall be automatically
annulled if the holders of any Indebtedness described in such section have
rescinded the declaration of acceleration in respect of such Indebtedness within
30 days from the date of such declaration and if: (1) the annulment of the
acceleration of the Notes would not conflict with any judgment or decree of a
competent jurisdiction and (2) all existing Events of Default, except
non-payment of principal or interest on the Notes that became due solely because
of the acceleration of the Notes, have been cured or waived.

            Subject to certain limitations, Holders of a majority in principal
amount of the then outstanding Notes may direct the Trustee in its exercise of
any trust or power. The Trustee may withhold from Holders of the Notes notice of
any continuing Default or Event of Default (except a Default or Event of Default
relating to the payment of principal or interest) if it determines that
withholding notice is in their interest. The Company is required to deliver to
the Trustee annually a statement regarding compliance with the Indenture, and
the Company is required, upon becoming aware of any Default or

<PAGE>

Event of Default, to deliver to the Trustee a statement specifying such Default
or Event of Default and what action the Company is taking or proposes to take
thereto.

            14. SUBSIDIARY GUARANTEES. Payment of principal of, premium, if any,
and interest (including interest on overdue principal, premium, if any, and
interest, if lawful) on the Notes is guaranteed on an unsecured, senior
subordinated basis by the Guarantors pursuant to Article XII of the Indenture.

            15. TRUSTEE DEALINGS WITH COMPANY. The Trustee, in its individual or
any other capacity, may make loans to, accept deposits from, and perform
services for the Company or its Affiliates, and may otherwise deal with the
Company or its Affiliates, as if it were not the Trustee.

            16. NO RECOURSE AGAINST OTHERS. No past, present or future director,
officer, employee, incorporator or stockholder, as such, of the Company or any
Guarantor shall have any liability for any obligations of the Company or any
Guarantor under the Notes, the Subsidiary Guarantees or the Indenture or for any
claim based on, in respect of or by reason of such obligations or their
creation. Each Holder by accepting a Note and the related Subsidiary Guarantees
waives and releases all such liability. The waiver and release are part of the
consideration for the issuance of the Notes.

            17. AUTHENTICATION. This Note shall not be valid until authenticated
by the manual signature of the Trustee or an authenticating agent.

            18. ABBREVIATIONS. Customary abbreviations may be used in the name
of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (=
tenants by the entireties), JT TEN (= joint tenants with right of survivorship
and not as tenants in common), CUST (= Custodian), and U/G/M/A (= Uniform Gifts
to Minors Act).

            19. CUSIP NUMBERS. Pursuant to a recommendation promulgated by the
Committee on Uniform Security Identification Procedures, the Company has caused
CUSIP numbers to be printed on the Notes and the Trustee may use CUSIP numbers
in notices of redemption as a convenience to Holders. No representation is made
as to the accuracy of such numbers either as printed on the Notes or as
contained in any notice of redemption and reliance may be placed only on the
other identification numbers placed thereon.

            The Company shall furnish to any Holder upon written request and
without charge a copy of the Indenture. Requests may be made to:

                   Iron Mountain Incorporated
                   745 Atlantic Avenue
                   Boston, Massachusetts 02111
                   Attention: Chief Financial Officer

<PAGE>

                                 ASSIGNMENT FORM

To assign this Note, fill in the form below: (I) or (we) assign and transfer
this Note to

--------------------------------------------------------------------------------
                  (Insert assignee's soc. sec. or tax I.D. no.)

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
              (Print or type assignee's name, address and zip code)

and irrevocably appoint ________________________________________________________
to transfer this Note on the books of the Company. The agent may substitute
another to act for him.

Date: __________

Your Signature: ________________________________________________________________
(Sign exactly as your name appears on the face of this Note)

Signature Guarantee:

<PAGE>

                       OPTION OF HOLDER TO ELECT PURCHASE

            If you want to elect to have this Note purchased by the Company
pursuant to Section 4.16 or 4.17 of the Indenture, check the box below:

                  |_| Section 4.16

                  |_| Section 4.17

            If you want to elect to have only part of the Note purchased by the
Company pursuant to Section 4.16 or 4.17 of the Indenture, state the amount you
elect to have purchased: $________


Date: __________                 Your Signature: _______________________________
                                 (Sign exactly as your name appears on the Note)

                                 Tax Identification No.: _______________________

Signature Guarantee:

<PAGE>

                         SCHEDULE OF EXCHANGES OF NOTES

            The following exchanges of a part of this Global Note for Definitive
Notes have been made:

<TABLE>
<CAPTION>
                                                                      Principal Amount of       Signature of
                      Amount of decrease    Amount of increase in      this Global Note       authorized office
                      in Principal Amount    Principal Amount of        following such          of Trustee or
Date of Exchange      of this Global Note      this Global Note     decrease (or increase)      Service Agent
----------------      -------------------      ----------------     ----------------------      -------------
<S>                   <C>                   <C>                     <C>                       <C>
</TABLE>

<PAGE>

                                    EXHIBIT B

       FORM OF SUPPLEMENTAL INDENTURE TO BE DELIVERED BY FUTURE GUARANTORS

            SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"), dated as of
________________, _____, between __________________ (the "Guarantor"), a
subsidiary of Iron Mountain Incorporated (or its successor), a Pennsylvania
corporation (the "Company"), and The Bank of New York, a New York banking
corporation, as trustee under the Indenture referred to below (the "Trustee").

                               W I T N E S S E T H

            WHEREAS, the Company has heretofore executed and delivered to the
Trustee an indenture, dated as of April 3, 2001, as supplemented by the First
Supplemental Indenture, dated as of April 3, 2001 (the indenture, as so
supplemented, the "Indenture") providing for the issuance of an aggregate
principal amount of $225,000,000 of 8"% Senior Subordinated Notes due 2013 (the
"Notes");

            WHEREAS, Section 4.13 of the Indenture provides that under certain
circumstances the Company is required to cause the Guarantor to execute and
deliver to the Trustee a supplemental indenture pursuant to which the Guarantor
shall unconditionally guarantee all of the Company's obligations under the Notes
pursuant to a Subsidiary Guarantee on the terms and conditions set forth herein;
and

            WHEREAS, pursuant to Section 9.1 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

            NOW THEREFORE, in consideration of the foregoing and for other good
and valuable consideration, the receipt of which is hereby acknowledged, the
Guarantor and the Trustee mutually covenant and agree for the equal and ratable
benefit of the Holders of the Notes as follows:

      1. CAPITALIZED TERMS. Capitalized terms used herein without definition
shall have the meanings assigned to them in the Indenture.

      2. AGREEMENT TO GUARANTEE. The Guarantor hereby agrees that its
obligations to the Holder and the Trustee pursuant to this Subsidiary Guarantee
shall be as expressly set forth in Article XII of the Indenture and in such
other provisions of the Indenture as are applicable to the Guarantors
(including, without limitation, Article XIII of the Indenture), and reference is
made to the Indenture for the precise terms of this Supplemental Indenture. The
terms of Article XII of the Indenture and such other provisions of the Indenture
(including, without limitation, Article XIII of the Indenture) as are applicable
to the Guarantors are incorporated herein by reference.

      3. EXECUTION AND DELIVERY OF SUBSIDIARY GUARANTEES.

<PAGE>

            (a) If an Officer whose signature is on this Supplemental Indenture
      no longer holds that office at the time the Trustee authenticates the
      Note, the Subsidiary Guarantee shall be valid nevertheless.

            (b) The delivery of any Note by the Trustee, after the
      authentication thereof under the Indenture, shall constitute due delivery
      of the Subsidiary Guarantee set forth in this Supplemental Indenture on
      behalf of the Guarantor.

      4. NO RECOURSE AGAINST OTHERS. No past, present or future director,
officer, employee, incorporator, stockholder of the Guarantor, as such, shall
have any liability for any obligations of the Company or any Guarantor under the
Notes, any Subsidiary Guarantee, the Indenture or this Supplemental Indenture or
for any claim based on, in respect of, or by reason of, such obligations or
their creation. Each Holder of the Notes by accepting a Note waives and releases
all such liability. The waiver and release are part of the consideration for
issuance of the Notes.

      5. NEW YORK LAW TO GOVERN. The internal law of the State of New York shall
govern and be used to construe this Supplemental Indenture and the Subsidiary
Guarantee.

      6. COUNTERPARTS. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

      7. EFFECT OF HEADINGS. The Section headings herein are for convenience
only and shall not affect the construction hereof.


                                      -2-
<PAGE>

            IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed, all as of the date first above written.

Dated: _______________, _______
                                          [Guarantor]

                                          By: __________________________________
                                              Name:
                                              Title:

Dated: _______________, _______
                                          The Bank of New York

                                          By: __________________________________
                                              Name:
                                              Title:


                                      -3-
</TEXT>
</DOCUMENT>
</SUBMISSION>
