<PAGE>

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                    FORM 10-Q


(Mark One)
\X\    Quarterly Report Pursuant to Section 13 or 15(d) of the Securities
       Exchange Act of 1934

              For the Quarterly Period Ended September 30, 1999

                                    or

\ \   Transition Report Pursuant to Section 13 or 15(d) of the Securities
      Exchange Act of 1934

                For the Transition Period from      to
                                               ----    ----

                         COMMISSION FILE NUMBER 1-14937


                           IRON MOUNTAIN INCORPORATED
             (Exact Name of Registrant as Specified in its Charter)


            DELAWARE                                    04-3107342
(State or Other Jurisdiction of               (IRS Employer Identification No.)
 Incorporation or Organization)


                      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
      ----              ----
As of November 5, 1999, there were 35,415,837 shares of the Registrant's Common
Stock, par value $0.01 per share, and no shares of the Registrant's Nonvoting
Common Stock, par value $0.01 per share, outstanding.


<PAGE>


                           IRON MOUNTAIN INCORPORATED
                                     INDEX

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

<S>      <C>                                                                                   <C>
Item 1 - Financial Statements

         Condensed Consolidated Balance Sheets at September 30, 1999 and
             December 31, 1998 (Unaudited)                                                          3

         Condensed Consolidated Statements of Operations for the Three Months Ended
             September 30, 1999 and 1998 (Unaudited)                                                4

         Condensed Consolidated Statements of Operations for the Nine Months Ended
             September 30, 1999 and 1998 (Unaudited)                                                5

         Condensed Consolidated Statements of Cash Flows for the Nine Months Ended
             September 30, 1999 and 1998 (Unaudited)                                                6

         Notes to Condensed Consolidated Financial Statements (Unaudited)                        7-16

Item 2 - Management's Discussion and Analysis of Financial Condition and Results of
             Operations                                                                         17-23

Item 3 - Quantitative and Qualitative Disclosures About Market Risk                                24


PART II - OTHER INFORMATION

Item 6 - Exhibits and Reports on Form 8-K                                                       24-25

          Signatures                                                                               26
</TABLE>



                                       2
<PAGE>

                           IRON MOUNTAIN INCORPORATED
                      CONDENSED CONSOLIDATED BALANCE SHEETS
                                 (In Thousands)
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                       SEPTEMBER 30,        DECEMBER 31,
                                                           1999                1998
                                                     -----------------   -----------------
<S>                                                  <C>                 <C>
ASSETS

CURRENT ASSETS:
   Cash and Cash Equivalents                            $     3,472      $     1,715
   Accounts Receivable (less allowances of $4,475
     and $3,316 respectively)                               106,115           75,565
   Foreign Currency Transaction Receivable                     --             45,885
   Deferred Income Taxes                                     12,528           10,474
   Prepaid Expenses and Other                                22,873           10,298
                                                        -----------      -----------
         Total Current Assets                               144,988          143,937

PROPERTY, PLANT AND EQUIPMENT:
   Property, Plant and Equipment                            477,889          354,101
   Less: Accumulated Depreciation                           (98,640)         (87,358)
                                                        -----------      -----------
         Property, Plant and Equipment, net                 379,249          266,743

OTHER ASSETS:
   Goodwill, net                                            724,578          527,235
   Customer Acquisition Costs, net                           14,985            9,574
   Deferred Financing Costs, net                             17,014           13,392
   Other                                                      7,110            6,504
                                                        -----------      -----------
         Total Other Assets                                 763,687          556,705
                                                        -----------      -----------

         Total Assets                                   $ 1,287,924      $   967,385
                                                        ===========      ===========

LIABILITIES AND STOCKHOLDERS' EQUITY

CURRENT LIABILITIES:
   Current Portion of Long-term Debt                    $     4,570      $     1,731
   Accounts Payable                                          19,543           20,620
   Accrued Expenses and Other                                60,776           48,878
   Foreign Currency Transaction Payable                        --             46,200
   Deferred Income                                           31,579           26,043
                                                        -----------      -----------
         Total Current Liabilities                          116,468          143,472

LONG-TERM DEBT, NET OF CURRENT PORTION                      598,493          454,447
OTHER LONG-TERM LIABILITIES                                   8,914            8,925
DEFERRED RENT                                                10,591            9,616
DEFERRED INCOME TAXES                                        20,946           12,043

MINORITY INTEREST                                            48,357             --

STOCKHOLDERS' EQUITY:
   Common Stock                                                 368              294
   Additional Paid-in Capital                               556,360          355,927
   Accumulated Deficit                                      (31,142)         (17,339)
   Accumulated Other Comprehensive Income                    (1,947)            --
   Treasury Stock                                           (39,484)            --
                                                        -----------      -----------
         Total Stockholders' Equity                         484,155          338,882
                                                        -----------      -----------

         Total Liabilities and Stockholders' Equity     $ 1,287,924      $   967,385
                                                        ===========      ===========
</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 SEPTEMBER 30,
                                                                -----------------------------------------
                                                                       1999                   1998
                                                                ------------------      -----------------
<S>                                                             <C>                     <C>
REVENUES:
   Storage                                                          $  82,339              $  59,506
   Service and Storage Material Sales                                  54,568                 39,038
                                                                    ---------              ---------

         Total Revenues                                               136,907                 98,544

OPERATING EXPENSES:
   Cost of Sales (Excluding Depreciation)                              69,226                 49,506
   Selling, General and Administrative                                 33,381                 24,069
   Depreciation and Amortization                                       16,338                 12,630
                                                                    ---------              ---------

         Total Operating Expenses                                     118,945                 86,205
                                                                    ---------              ---------

OPERATING INCOME                                                       17,962                 12,339

INTEREST EXPENSE                                                       14,075                 10,979
OTHER INCOME                                                              115                     --
                                                                    ---------              ---------

         Income from Continuing Operations Before Provision for
           Income Taxes and Minority Interest                           4,002                  1,360

PROVISION FOR INCOME TAXES                                              2,953                  2,378
MINORITY INTEREST                                                          50                     --
                                                                    ---------              ---------

         Income (Loss) from Continuing Operations                         999                 (1,018)

LOSS FROM DISCONTINUED OPERATIONS (NET OF APPLICABLE TAXES)                --                    (51)
LOSS ON SALE OF DISCONTINUED OPERATIONS                                (4,000)                    --
                                                                    ---------              ---------

         Net Loss                                                   $  (3,001)            $  (1,069)
                                                                    =========              =========

NET LOSS PER COMMON SHARE - BASIC AND DILUTED:
   Income (Loss) from Continuing Operations                         $    0.03             $   (0.03)
   Loss from Discontinued Operations (Net of Applicable Taxes)           --                   (0.01)
   Loss on Sale of Discontinued Operations                              (0.11)                    --
                                                                    ---------              ---------
         Net Loss Per Common Share - Basic and Diluted              $   (0.08)            $   (0.04)
                                                                    =========              =========

WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
         Basic                                                         35,331                29,209
                                                                    =========              =========

         Diluted                                                       36,196                29,209
                                                                    =========              =========
</TABLE>

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


                                       4
<PAGE>


                           IRON MOUNTAIN INCORPORATED
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                    NINE MONTHS ENDED SEPTEMBER 30,
                                                               ---------------------------------------
                                                                      1999                 1998
                                                               ------------------     ----------------
<S>                                                            <C>                    <C>
REVENUES:
   Storage                                                           $ 229,989            $ 168,046
   Service and Storage Material Sales                                  148,054              113,018
                                                                     ---------            ---------

         Total Revenues                                                378,043              281,064

OPERATING EXPENSES:
   Cost of Sales (Excluding Depreciation)                              189,828              141,179
   Selling, General and Administrative                                  94,194               70,067
   Depreciation and Amortization                                        46,214               35,591
                                                                     ---------            ---------

         Total Operating Expenses                                      330,236              246,837
                                                                     ---------            ---------

OPERATING INCOME                                                        47,807               34,227

INTEREST EXPENSE                                                        40,246               34,166
OTHER INCOME                                                               115                1,700
                                                                     ---------            ---------

         Income from Continuing Operations Before Provision for
           Income Taxes and Minority Interest                            7,676                1,761

PROVISION FOR INCOME TAXES                                               7,805                3,720
MINORITY INTEREST                                                          515                   --
                                                                     ---------            ---------

         Loss from Continuing Operations                                  (644)              (1,959)

INCOME FROM DISCONTINUED OPERATIONS (NET OF APPLICABLE TAXES)              241                  315

LOSS ON SALE OF DISCONTINUED OPERATIONS                                (13,400)                  --
                                                                     ---------            ---------

         Net Loss                                                    $ (13,803)          $   (1,644)
                                                                     =========            =========

NET LOSS PER COMMON SHARE - BASIC AND DILUTED:
   Loss from Continuing Operations                                   $   (0.02)          $    (0.07)
   Income from Discontinued Operations (Net of Applicable Taxes)          0.01                 0.01
   Loss on Sale of Discontinued Operations                           $   (0.41)                 --
                                                                     ---------            ---------
         Net Loss Per Common Share - Basic and Diluted               $   (0.42)          $    (0.06)
                                                                     =========            =========

WEIGHTED AVERAGE COMMON SHARES OUTSTANDING - BASIC AND DILUTED          32,641               26,848
                                                                     =========            =========
</TABLE>

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

                                       5
<PAGE>

                           IRON MOUNTAIN INCORPORATED
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                                    NINE MONTHS ENDED SEPTEMBER 30,
                                                                                ----------------------------------------
                                                                                     1999                    1998
                                                                                -----------------    -------------------
<S>                                                                             <C>                  <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
   Net Loss                                                                       $ (13,803)              $  (1,644)
   Adjustments to reconcile net loss to loss from continuing operations:
     Income from Discontinued Operations                                               (241)                   (315)
     Loss on sale of Discontinued Operations                                         13,400                      --
                                                                                  ---------                ---------
   Loss from Continuing Operations                                                     (644)                 (1,959)
   Adjustments  to Reconcile  Loss from  Continuing  Operations to Cash Flows
     Provided by Operating Activities of Continuing Operations:
     Minority Interest                                                                5,295                      --
     Depreciation and Amortization                                                   46,214                  35,591
     Amortization of Financing Costs                                                  1,455                   1,350
     Provision for Doubtful Accounts                                                  1,580                   1,236
     Other, net                                                                         (97)                     --
   Changes in Assets and Liabilities (Exclusive of Acquisitions):
     Accounts Receivable                                                            (18,653)                 (6,305)
     Prepaid Expenses and Other Current Assets                                      (10,186)                  8,196
     Deferred Income Taxes                                                            7,248                   2,490
     Other Assets                                                                       139                     967
     Accounts Payable                                                                (4,947)                 (5,709)
     Accrued Expenses and Other Current Liabilities                                  (1,283)                  1,889
     Deferred Income                                                                  1,422                     537
     Deferred Rent                                                                      975                   1,107
     Other Long-term Liabilities                                                         (9)                  4,170
                                                                                  ---------               ---------
              Cash Flows Provided by Continuing Operations                           28,509                  43,560
              Cash Flows Provided by Discontinued Operations                            790                   1,171
                                                                                  ---------               ---------
              Cash Flows Provided by Operating Activities                            29,299                  44,731

CASH FLOWS FROM INVESTING ACTIVITIES:
   Cash Paid for Acquisitions                                                      (187,513)               (175,029)
   Capital Expenditures                                                             (72,769)                (36,957)
   Additions to Customer Acquisition Costs                                           (6,061)                 (2,326)
                                                                                  ---------                ---------
              Cash Flows Used in Continuing Operations                             (266,343)               (214,312)
              Cash Flows Used in Discontinued Operations                               (409)                   (262)
                                                                                  ---------                ---------
              Cash Flows Used in Investing Activities                              (266,752)               (214,574)

CASH FLOWS FROM FINANCING ACTIVITIES:
   Repayment of Debt                                                               (236,420)               (142,286)
   Proceeds from Borrowings                                                         216,744                 153,600
   Net Proceeds from Sale of  Senior Subordinated Notes                             149,460                      --
   Financing Costs                                                                   (5,077)                   (344)
   Net Proceeds from Equity Offering                                                153,755                 132,905
   Repurchase of Common Stock                                                       (39,484)                     --
   Proceeds from Exercise of Stock Options                                            1,518                   2,961
   Stock Issuance Costs                                                              (1,220)                   (981)
                                                                                  ---------               ---------
              Cash Flows Provided by Continuing Operations                          239,276                 145,855
              Cash Flows Provided by Discontinued Operations                           --                        --
                                                                                  ---------               ---------
              Cash Flows Provided by Financing Activities                           239,276                 145,855

EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS                                   (66)                     --
                                                                                  ---------               ---------

INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                      1,757                 (23,988)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD                                        1,715                  24,510
                                                                                  ---------               ---------
CASH AND CASH EQUIVALENTS, END OF PERIOD                                              3,472                     522
                                                                                  =========               =========
</TABLE>

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


                                       6
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (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, 1998, 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 related
notes for the year ended December 31, 1998 included in the Company's Current
Report on Form 8-K filed with the Securities and Exchange Commission on July 9,
1999.

(2)      COMPREHENSIVE INCOME (LOSS)

Statement of Financial Accounting Standards 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                  NINE MONTHS ENDED
                                                             SEPTEMBER 30,                      SEPTEMBER 30,
                                                ------------------------------------    ------------------------------
                                                      1999                1998              1999             1998
                                                -----------------    ---------------    -------------    -------------
<S>                                             <C>                  <C>                <C>              <C>
Comprehensive Loss:
   Net Loss                                     $ (3,001)             $ (1,069)           $(13,803)        $ (1,644)
   Other Comprehensive Income (Loss):
    Foreign Currency Translation Adjustment          340                    --              (1,947)              --
                                                --------              --------            --------         --------
Comprehensive Loss                              $ (2,661)             $ (1,069)           $(15,750)        $ (1,644)
                                                ========              ========            ========         ========
</TABLE>


                                       7
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)


(3)    ACQUISITIONS

During the nine months ended September 30, 1999, the Company: (i) purchased a
controlling 50.1% interest in Britannia Data Management Limited ("BDM"), a
provider of records and information management services in the United
Kingdom; (ii) purchased substantially all of the assets, and assumed certain
liabilities, of 11 records and information management businesses, including
BDM's acquisition of Memogarde, S.A.; and (iii) invested in Sistemas de
Archivo Corporativo ("SAC"), a provider of records and information management
services in Mexico, to gain a controlling 50.1% interest and to infuse growth
capital (collectively, the "1999 Acquisitions"). Each of the 1999
Acquisitions and all 15 of the records and information management businesses
acquired during 1998 (the "1998 Acquisitions"), 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
1999 and 1998 acquisitions, related real estate was also purchased. The
aggregate purchase price for the 1999 Acquisitions was comprised of cash, the
Company's common stock and the capital stock of Arcus Data Security Limited
("ADS"), the Company's existing data security business in London, and
exceeded the underlying fair value of the net assets acquired by $165,458,
which has been assigned to goodwill and is being amortized over 25 to 30
years. The $63,586 of goodwill recorded by BDM relates to the 1996
acquisition of BDM by Mentmore Abbey plc. The purchase price allocations are
preliminary and subject to adjustment.

A summary of the total consideration and the preliminary allocation of the
aggregate purchase price of the 1999 Acquisitions, as of the acquisition dates,
is as follows:
<TABLE>
<S>                                            <C>
Purchase Price:
    Cash Paid                                   $ 187,513
    Fair Value of Common Stock Issued              46,000
    Fair Value of ADS Capital Stock                 2,489
                                                ---------
         Total Purchase Price                   $ 236,002
                                                =========

 Allocation of Purchase Price:
    Current Assets                              $  23,331
    Property, Plant & Equipment                    64,561
    Other Assets                                    1,647
    Fair Value of ADS Net Assets                    2,489
    Goodwill Recorded by BDM                       63,586
    Goodwill Recorded by Iron Mountain            165,458
    Liabilities Assumed                           (45,747)
    Minority Interest                             (39,323)
                                                ---------
         Total Allocation of Purchase Price     $ 236,002
                                                =========
</TABLE>


In May 1999, the Company repurchased for $39,484 all of the 1,476,577 shares of
its common stock issued in connection with a certain 1999 Acquisition. These
shares had a fair value of $46,000 when issued.


                                       8
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(3)      ACQUISITIONS (CONTINUED)

In September 1999, BDM acquired Stortext (Holdings) Limited and Datavault, S.A.
for approximately $22 million in cash and assumed debt. Stortext operates seven
facilities in Edinburgh and Glasgow, Scotland and Datavault operates seven
facilities in five markets in Spain including Madrid and Bilbao. Due to the
two-month difference in fiscal year ends between the Company and BDM, BDM's
acquisitions of Stortext and Datavault are not reflected in the accompanying
condensed consolidated financial statements and notes thereto.

      The following unaudited pro forma information shows the results of the
      Company's operations for the nine months ended September 30, 1999 and the
      year ended December 31, 1998, as though each of the 1999 and 1998
      Acquisitions, except Stortext (Holdings) Limited and Datavault, S.A., had
      occurred as of the beginning of the respective period:
<TABLE>
<CAPTION>
                                                                                             YEAR
                                                                 NINE MONTHS ENDED           ENDED
                                                                   SEPTEMBER 30,          DECEMBER 31,
                                                                       1999                  1998
                                                                 -----------------     ----------------
<S>                                                              <C>                   <C>
Revenues                                                           $ 399,320               $ 480,843

Loss from Continuing Operations                                       (1,540)                (10,003)

 Loss from Continuing Operations Per Share - Basic and Diluted         (0.05)                  (0.34)
</TABLE>

The pro forma results have been prepared for comparative purposes only and are
not necessarily indicative of the actual results of operations had the
acquisitions taken place as of the beginning of each period or the results that
may occur in the future. Furthermore, the pro forma results do not give effect
to all cost savings or incremental costs which may occur as a result of the
integration and consolidation of the businesses.


                                       9
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(4)    LONG-TERM DEBT

Long-term debt consists of the following:
<TABLE>
<CAPTION>
                                                     SEPTEMBER 30, 1999                    DECEMBER 31, 1998
                                             ----------------------------------   ---------------------------------
                                                 CARRYING          FAIR              CARRYING            FAIR
                                                  AMOUNT           VALUE              AMOUNT             VALUE
                                              --------------   -------------      --------------     --------------
<S>                                           <C>              <C>                <C>                <C>
8-1/4% Senior Subordinated Notes (the
   "1999 Notes")                                $ 149,479        $ 135,750           $    --            $    --
8-3/4% Senior Subordinated Notes (the
   "1997 Notes")                                  249,596          235,000           249,566            257,500
10-1/8% Senior Subordinated Notes (the
   "1996 Notes")                                  165,000          167,475           165,000            178,200
Revolving Credit Facility                              --               --            35,300             35,300
Real Estate Mortgages                               2,123            2,123             2,349              2,349
Other                                              36,865           36,865             3,963              3,963
                                                ---------                          ---------
   Total Long-term Debt                           603,063                            456,178
Less: Current Portion                              (4,570)                            (1,731)
                                                ---------                          ---------
Long-term Debt, Net of Current Portion
                                                $ 598,493                          $ 454,447
                                                =========                          =========
</TABLE>


The estimated fair values for the long-term debt are based on the borrowing
rates available to the Company at September 30, 1999 and December 31, 1998 for
loans with similar terms and average maturities. The fair values of the 1996
Notes, 1997 Notes and 1999 Notes are based on the quoted market prices for those
notes on September 30, 1999 and December 31, 1998.


                                       10
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

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

    The 1996 Notes, the 1997 Notes and the 1999 Notes are fully and
    unconditionally guaranteed, on a joint and several senior subordinated
    basis, by most, but not all, of the Company's direct and indirect
    subsidiaries (the "Guarantors"). Currently, BDM and its subsidiaries, SAC
    and its subsidiaries, Iron Mountain (Puerto Rico), Inc. and certain parent
    holding companies (the "Non-Guarantors") are the only subsidiaries that do
    not guarantee the 1996 Notes, the 1997 Notes or the 1999 Notes.

    Prior to the acquisition of BDM in January 1999, substantially all of the
    Company's operations were conducted by its direct and indirect wholly owned
    subsidiaries, all of which, other than ADS, were guarantors of the 1996
    Notes and 1997 Notes. ADS represented less than 1% of the Company's
    consolidated revenues and was not material to its results of operations. The
    Company's management does not believe that separate financial statements of,
    and other disclosures with respect to, the Guarantors for periods prior to
    1999 are meaningful or material to investors. Accordingly, no such financial
    statements were provided.

    The following financial data summarizes the consolidating Company on the
    equity method of accounting as of and for the three and nine month periods
    September 30, 1999:
<TABLE>
<CAPTION>
                                                                              SEPTEMBER 30, 1999
                                                    ------------------------------------------------------------------------
                                                                                     NON-
                                                        PARENT      GUARANTORS    GUARANTORS   ELIMINATIONS   CONSOLIDATED
                                                     ----------    -----------   -----------   ------------   ------------
<S>                                                  <C>           <C>           <C>           <C>            <C>
ASSETS
CURRENT ASSETS:
   Cash and Cash Equivalents                         $       --    $    1,422    $     2,050   $        --    $      3,472
   Accounts Receivable                                       --        98,425          7,690            --         106,115
   Other Current Assets                                      --        30,741          5,325          (665)         35,401
                                                     ----------    ----------    -----------   -----------    ------------
    Total Current Assets                                     --       130,588         15,065          (665)        144,988
PROPERTY, PLANT AND EQUIPMENT, NET                           --       334,688         44,561            --         379,249
OTHER ASSETS:
   Due From Affiliates                                  214,543            --             --      (214,543)             --
   Long-term Notes Receivable from Affiliates           549,867            --             --      (549,867)             --
   Investment in Subsidiaries                           279,818        56,583             --      (336,401)             --
   Goodwill, net                                             --       634,033         90,545            --         724,578
   Other                                                 16,297        22,209            603            --          39,109
                                                     ----------    ----------    -----------   -----------    ------------
    Total Other Assets                                1,060,525       712,825         91,148    (1,100,811)        763,687
                                                     ----------    ----------    -----------   -----------    ------------

    Total Assets                                     $1,060,525    $1,178,101    $   150,774   $(1,101,476)   $  1,287,924
                                                     ==========    ==========    ===========   ===========    ============

LIABILITIES AND STOCKHOLDERS' EQUITY
TOTAL CURRENT LIABILITIES                                11,395        93,865         11,873          (665)        116,468
LONG-TERM DEBT, NET OF CURRENT PORTION                  564,975         3,206         30,312            --         598,493
DUE TO AFFILIATES                                            --       214,543             --      (214,543)             --
LONG-TERM NOTES PAYABLE TO AFFILIATES                        --       549,867             --      (549,867)             --
OTHER LONG-TERM LIABILITIES                                  --        39,397          1,054            --          40,451
MINORITY INTEREST                                            --            --         48,357            --          48,357
STOCKHOLDERS' EQUITY                                    484,155       277,223         59,178      (336,401)        484,155
                                                     ----------    ----------    -----------   -----------    ------------
  Total Liabilities and Stockholders' Equity         $1,060,525    $1,178,101    $   150,774   $(1,101,476)   $  1,287,924
                                                     ==========    ==========    ===========   ===========    ============
</TABLE>


                                       11
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(5)    SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND NON-
       GUARANTORS (CONTINUED)
<TABLE>
<CAPTION>
                                                                   THREE MONTHS ENDED SEPTEMBER 30, 1999
                                                  ----------------------------------------------------------------------
                                                                                 NON-
                                                     PARENT     GUARANTORS     GUARANTORS    ELIMINATIONS  CONSOLIDATED
                                                   ---------    ----------   -----------     ------------  ------------
<S>                                                <C>         <C>           <C>             <C>            <C>
REVENUES:
   Storage                                         $      --    $   76,880   $     5,459     $        --     $   82,339
   Service and Storage Material Sales                     --        50,711         3,857              --         54,568
                                                   ---------    ----------   -----------     -----------     ----------
    Total Revenues                                        --       127,591         9,316              --        136,907

OPERATING EXPENSES:
   Cost of Sales (Excluding Depreciation)                 --        64,044         5,182              --         69,226
   Selling, General and Administrative                    31        31,298         2,052              --         33,381
   Depreciation and Amortization                          --        15,180         1,158              --         16,338
                                                   ---------    ----------   -----------     -----------     ----------
    Total Operating Expenses                              31       110,522         8,392              --        118,945
                                                   ---------    ----------   -----------     -----------     ----------

OPERATING INCOME (LOSS)                                  (31)       17,069           924              --         17,962

INTEREST INCOME                                      (13,746)           --            --          13,746             --
INTEREST EXPENSE                                      13,553        13,932           336         (13,746)        14,075
EQUITY IN THE (EARNINGS) LOSSES OF SUBSIDIARIES
                                                       3,163            32            --          (3,195)            --
OTHER INCOME                                              --           115            --              --            115
                                                   ---------    ----------   -----------     -----------     ----------

    Income (Loss) from Continuing Operations
       Before Provision for Income Taxes and
       Minority Interest                              (3,001)        3,220           588           3,195          4,002

PROVISION FOR INCOME TAXES                                --         2,553           400              --          2,953
MINORITY INTEREST IN NET INCOME OF CONSOLIDATED
  SUBSIDIARIES                                            --            --            50              --             50
                                                   ---------    ----------   -----------     -----------     ----------
    Income (Loss) from Continuing Operations          (3,001)          667           138           3,195            999

LOSS ON SALE OF DISCONTINUED OPERATIONS                   --        (4,000)           --              --         (4,000)
                                                   ---------    ----------   -----------     -----------     ----------

         Net Income (Loss)                        $   (3,001)   $   (3,333)  $       138     $     3,195    $    (3,001)
                                                  ==========    ==========   ===========     ===========    ===========
</TABLE>


                                       12
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(5)    SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND NON-
       GUARANTORS (CONTINUED)
<TABLE>
<CAPTION>
                                                                   NINE MONTHS ENDED SEPTEMBER 30, 1999
                                                  ----------------------------------------------------------------------
                                                                                 NON-
                                                     PARENT     GUARANTORS    GUARANTORS     ELIMINATIONS  CONSOLIDATED
                                                   ---------    -----------  ------------    ------------  ------------
<S>                                               <C>           <C>          <C>            <C>             <C>
REVENUES:
   Storage                                         $      --    $   217,914  $    12,075     $        --     $  229,989
   Service and Storage Material Sales                     --        139,081        8,973              --        148,054
                                                   ---------    -----------  -----------     -----------     ----------
    Total Revenues                                        --        356,995       21,048              --        378,043

OPERATING EXPENSES:
   Cost of Sales (Excluding Depreciation)                 --        177,861       11,967              --        189,828
   Selling, General and Administrative                   216         90,125        3,853              --         94,194
   Depreciation and Amortization                          --         43,653        2,561              --         46,214
                                                   ---------    -----------  -----------     -----------     ----------
    Total Operating Expenses                             216        311,639       18,381              --        330,236
                                                   ---------    -----------  -----------     -----------     ----------

OPERATING INCOME (LOSS)                                 (216)        45,356        2,667              --         47,807

INTEREST INCOME                                      (37,858)            --           --          37,858             --
INTEREST EXPENSE                                      39,142         38,309          653         (37,858)        40,246
EQUITY IN THE (EARNINGS) LOSSES OF SUBSIDIARIES
                                                      12,303           (328)          --         (11,975)            --
OTHER INCOME                                              --            115           --              --            115
                                                   ---------    -----------  -----------     -----------     ----------

    Income (Loss) from Continuing Operations
       Before Provision for Income Taxes and
       Minority Interest                             (13,803)         7,490        2,014          11,975          7,676

PROVISION FOR INCOME TAXES                                --          6,831          974              --          7,805
MINORITY INTEREST IN NET INCOME OF CONSOLIDATED
  SUBSIDIARIES                                            --             --          515              --            515
                                                   ---------    -----------  -----------     -----------     ----------
    Income (Loss) from Continuing Operations         (13,803)           659          525          11,975           (644)

INCOME FROM DISCONTINUED OPERATIONS (NET OF
  APPLICABLE TAXES)                                       --            241           --              --            241
LOSS ON SALE OF DISCONTINUED OPERATIONS                   --        (13,400)          --              --        (13,400)
                                                   ---------    -----------  -----------     -----------     ----------

         Net Income (Loss)                         $ (13,803)   $   (12,500) $       525     $    11,975     $  (13,803)
                                                   =========    ===========  ===========     ===========     ==========
</TABLE>


                                       13
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(5)    SELECTED CONSOLIDATED FINANCIAL STATEMENTS OF PARENT, GUARANTORS AND NON-
       GUARANTORS (CONTINUED)
<TABLE>
<CAPTION>

                                                                             NINE MONTHS ENDED SEPTEMBER 30, 1999
                                                             ----------------------------------------------------------------------
                                                                                          NON-
                                                                PARENT     GUARANTORS   GUARANTORS  ELIMINATIONS  CONSOLIDATED
                                                               ---------   ----------   ----------  ------------  ------------
<S>                                                            <C>         <C>          <C>         <C>           <C>
CASH FLOWS FROM OPERATING ACTIVITIES
  Cash Flows (Used in) Provided by Continuing Operations
                                                               $(27,505)    $ 53,581     $   2,433           --   $  28,509
  Cash Flows Provided by Discontinued Operations                     --          790            --           --         790
                                                               ---------    ---------    ---------    ---------   ---------
      Cash Flows (Used in) Provided by Operating Activities     (27,505)      54,371         2,433           --      29,299


CASH FLOWS FROM INVESTING ACTIVITIES:
  Cash Paid for Acquisitions                                     (2,398)    (125,327)      (59,788)          --    (187,513)
  Capital Expenditures                                               --      (60,497)      (12,272)          --     (72,769)
  Intercompany Loans to Subsidiaries                           (139,129)          --            --      139,129          --
  Investment in Subsidiaries                                    (55,599)     (55,599)           --      111,198          --
    Additions to Customer Acquisition Costs                          --       (6,061)           --           --      (6,061)
                                                               ---------    ---------    ---------    ---------    ---------
    Cash Flows Used in Continuing Operations                   (197,126)    (247,484)      (72,060)     250,327    (266,343)
      Cash Flows Used in Discontinued Operations                     --         (409)          --           --         (409)
                                                               ---------    ---------    ---------    ---------    ---------
      Cash Flows Used in Investing Activities                  (197,126)    (247,893)      (72,060)     250,327    (266,752)

CASH FLOWS FROM FINANCING ACTIVITIES:
  Repayment of Debt                                            (235,000)      (1,420)          --           --     (236,420)
  Net Proceeds from Borrowings                                  200,600           --        16,144          --      216,744
  Net Proceeds from Sale of Senior Subordinated Notes           149,460           --           --           --      149,460
  Net Proceeds from Equity Offering                             153,755           --           --           --      153,755
  Repurchase of Common Stock                                    (39,484)          --           --           --      (39,484)
  Intercompany Loans from Parent                                     --      139,129           --     (139,129)          --
  Equity Contribution from Parent                                    --       55,599        55,599    (111,198)          --
  Proceeds from Exercise of Stock Options                         1,518           --           --           --        1,518
  Debt Financing and Stock Issuance Costs                        (6,230)         (67)          --           --       (6,297)
                                                              ---------    ---------    ---------    ---------      ---------
      Cash Flows Provided by Continuing Operations              224,619      193,241       71,743     (250,327)     239,276
      Cash Flows Provided by Discontinued Operations                 --           --           --           --           --
                                                              ---------    ---------    ---------    ---------       --------
      Cash Flows Provided by Financing Activities               224,619      193,241       71,743     (250,327)     239,276

EFFECT OF EXCHANGE RATES ON CASH AND CASH
   EQUIVALENTS                                                       --           --          (66)          --          (66)
                                                              ---------    ---------    ---------    ---------       --------

INCREASE (DECREASE) IN CASH AND CASH
   EQUIVALENTS                                                      (12)        (281)       2,050           --        1,757

CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD                       12        1,703           --           --        1,715
                                                              ---------    ---------    ---------    ---------      ---------

CASH AND CASH EQUIVALENTS, END OF PERIOD                        $    --    $   1,422    $   2,050    $      --      $ 3,472
                                                              =========    =========    =========    =========      =========
</TABLE>



                                       14
<PAGE>

                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(6)    EARNINGS PER SHARE

In accordance with Statement of Financial Accounting Standards No. 128, 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 dilutive potential
common shares (that is, securities such as options, warrants or convertible
securities) that were outstanding during the period, unless the effect is
antidilutive. For the nine months ended September 30, 1999 and 1998 and the
three months ended September 30, 1998, 2,344, 2,341 and 2,341 potential
common shares, respectively, have been excluded from the calculation of
diluted net income (loss) per share, as their effects are antidilutive.

(7)    DISCONTINUED OPERATIONS

In June 1999, the Company decided to sell its information technology staffing
business, Arcus Staffing Resources, Inc. ("Arcus Staffing"). Arcus Staffing
was acquired in January 1998 as part of the acquisition of Arcus Group, Inc.
In accordance with the provisions of Accounting Principles Board Opinion No.
30 concerning reporting the effect of the disposal of a business, the results
of operations of Arcus Staffing have been classified as discontinued in the
accompanying statements of operations for the three and nine month periods
ended September 30, 1999 and 1998. The following table sets forth the revenue
and net income (loss) from discontinued operations for all of the periods
presented:

<TABLE>
<CAPTION>

                                  Three Months Ended                   Nine Months Ended
                                     September 30,                       September 30,
                            --------------------------------     ------------------------------
                                 1999              1998              1999             1998
                            ---------------    -------------     -------------    -------------
<S>                         <C>                <C>              <C>               <C>
Revenues                        $10,196          $ 9,416             $32,188         $29,443

Net Income (Loss) from
  Discontinued Operations          --                (51)                241             315

</TABLE>


The Company has recorded an estimated loss on the sale of Arcus Staffing of
$13,400. The estimated loss is comprised of a write-off of nondeductible and
deductible goodwill, a deferred tax benefit and estimated expenses directly
related to the transaction partially offset by the estimated income from
operations of Arcus Staffing through the date of disposition. Effective
November 1, 1999, the Company completed the sale of substantially all of the
assets of Arcus Staffing.


                                       15
<PAGE>


                           IRON MOUNTAIN INCORPORATED
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                      (In Thousands except Per Share Data)
                                   (Unaudited)

                                   (Continued)

(8) SUBSEQUENT EVENTS

In October 1999, the Company acquired substantially all of the assets of one
records and information management business for approximately $8 million in
cash.

On October 21, 1999, the Company announced the execution of a definitive
agreement to acquire Pierce Leahy Corp. in a stock-for-stock merger valued at
approximately $1.1 billion including the assumption of approximately $583
million in outstanding Pierce Leahy debt. The merger consideration will result
in the equivalent of a fixed exchange ratio of 1.1 shares of Iron Mountain
common stock for each share of Pierce Leahy common stock. The proposed
transaction is subject to approval by the shareholders of both companies, the
completion of regulatory review and other customary conditions. The transaction
is expected to be completed in early 2000 and will be accounted for as a
purchase.


                                       16
<PAGE>


                           IRON MOUNTAIN INCORPORATED
                     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 and nine month periods ended
    September 30, 1999 and 1998 should be read in conjunction with the
    consolidated financial statements and footnotes for the three and nine month
    periods ended September 30, 1999 included herein, and the year ended
    December 31, 1998, included in the Company's Current Report on Form 8-K
    filed with the Securities and Exchange Commission on July 9, 1999.


    OVERVIEW

    The Company's consolidated revenues increased $38.4 million, or 38.9%, to
    $136.9 million for the third quarter of 1999 from $98.5 million for the
    third quarter of 1998. Internal revenue growth was 15.2%. For the nine
    months ended September 30, 1999, the Company's consolidated revenues were
    $378.0 million compared to $281.1 million for the same period last year, an
    increase of 34.5%. Internal revenue growth was 12.7%.

    On April 26, 1999, the Company completed the sale, in a private placement to
    qualified institutional buyers, of $150 million in aggregate principal
    amount of its 8 1/4% Senior Subordinated Notes due 2011. The 1999 Notes were
    issued at a price to investors of 99.64% of par. On May 17, 1999, the
    Company completed an underwritten public offering of 5,750,000 shares of its
    common stock (the "Equity Offering") at a price to the public of $28.00 per
    share (including 750,000 shares as a result of the underwriters' exercise of
    their overallotment option). The net proceeds from these financing
    transactions were used to repurchase all of the 1,476,577 shares of the
    common stock issued in the acquisition of Data Base, Inc. at a price of
    $26.74 per share, to repay outstanding indebtedness under the Company's
    revolving credit facility and for general corporate purposes, including
    acquisitions.

    In June 1999, in order to focus on its records and information management
    services business, the Company decided to sell its information technology
    staffing business, Arcus Staffing, which was acquired in January 1998 as
    part of the acquisition of Arcus Group, Inc. The sale of Arcus Staffing is
    being accounted for as a discontinued operation. Accordingly, the Arcus
    Staffing operations have been segregated from the Company's continuing
    operations and reported as a separate line item on the Company's statement
    of operations. For the nine months ended September 30, 1999, the Company
    recorded an estimated loss on the sale of Arcus Staffing of $13.4 million
    comprised primarily of the write-off of nondeductible goodwill. Effective
    November 1, 1999, the Company completed the sale of substantially all of
    the assets of Arcus Staffing.

    On October 21, 1999, the Company announced the execution of a definitive
    agreement to acquire Pierce Leahy Corp. in a stock-for-stock merger valued
    at approximately $1.1 billion including the assumption of approximately $583
    million in outstanding Pierce Leahy debt. The merger consideration will
    result in the equivalent of a fixed exchange ratio of 1.1 shares of Iron
    Mountain common stock for each share of Pierce Leahy common stock. The
    acquisition is structured as a reverse merger where Pierce Leahy Corp. will
    be the surviving legal entity and will change its name to Iron Mountain
    Incorporated. The proposed transaction is subject to approval by the
    shareholders of both companies, the completion of regulatory review and
    other customary conditions. The transaction is expected to be completed in
    early 2000 and will be accounted for as a purchase.


                                       17
<PAGE>


                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)

    RESULTS OF OPERATIONS

    THREE MONTHS ENDED SEPTEMBER 30, 1999 COMPARED TO THREE MONTHS
    ENDED SEPTEMBER 30, 1998

    Consolidated storage revenues increased $22.8 million, or 38.4%, to $82.3
    million for the third quarter of 1999 from $59.5 million for the third
    quarter of 1998. Internal storage revenue growth was 10.3%. The internal
    storage revenue growth resulted primarily from net increases in records and
    other media stored by existing customers and from sales to new customers.

    Consolidated service and storage material sales revenues increased $15.6
    million, or 39.8%, to $54.6 million for the third quarter of 1999 from $39.0
    million for the third quarter of 1998. Internal service and storage material
    sales revenue growth was 22.5%. The internal revenue growth resulted from
    increases in service and storage material sales to existing customers and
    the addition of new customer accounts.

    For the reasons discussed above, total consolidated revenues increased
    $38.4 million, or 38.9%, to $136.9 million for the third quarter of 1999
    from $98.5 million for the third quarter of 1998.

    Consolidated cost of sales (excluding depreciation) increased $19.7 million,
    or 39.8%, to $69.2 million (50.6% of consolidated revenues) for the third
    quarter of 1999 from $49.5 million (50.2% of consolidated revenues) for the
    third quarter of 1998. The dollar increase was primarily attributable to the
    increase in records and other media stored and expenses related to certain
    facility moves.

    Consolidated selling, general and administrative expenses increased $9.3
    million, or 38.7%, to $33.4 million (24.4% of consolidated revenues) for the
    third quarter of 1999 from $24.1 million (24.4% of consolidated revenues)
    for the third quarter of 1998. The dollar increase was primarily
    attributable to: (i) the adoption, effective January 1, 1999, of Statement
    of Position 98-1, "Accounting for the Costs of Computer Software Developed
    or Obtained for Internal Use" which requires certain computer software costs
    associated with internal use software to be expensed as incurred and (ii)
    increased personnel, office and overhead costs to support the Company's
    growth.

    Consolidated depreciation and amortization expense increased $3.7 million,
    or 29.4%, to $16.3 million (11.9% of consolidated revenues) for the third
    quarter of 1999 from $12.6 million (12.8% of consolidated revenues) for the
    third quarter of 1998. The dollar increase was primarily attributable to the
    additional depreciation and amortization expense related to the 1998 and
    1999 Acquisitions, and capital expenditures including racking systems,
    information systems and expansion of storage capacity in existing
    facilities.

    As a result of the foregoing factors, consolidated operating income
    increased $5.7 million, or 45.6%, to $18.0 million (13.1% of consolidated
    revenues) for the third quarter of 1999 from $12.3 million (12.5% of
    consolidated revenues) for the third quarter of 1998.

    Consolidated interest expense increased $3.1 million, or 28.2%, to $14.1
    million for the third quarter of 1999 from $11.0 million for the third
    quarter of 1998. The increase was primarily attributable to increased
    indebtedness related to the financing of acquisitions and capital
    expenditures. The increase was partially offset by lower effective interest
    rates for the third quarter of 1999 compared to the same period in 1998.


                                       18
<PAGE>


                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)

    Consolidated other income for the third quarter of 1999 is comprised of a
    $0.1 million net foreign currency exchange gain.

    As a result of the foregoing factors, consolidated income from continuing
    operations before provision for income taxes and minority interest increased
    $2.6 million to $4.0 million (2.9% of consolidated revenues) for the third
    quarter of 1999 from $1.4 million (1.4% of consolidated revenues) for the
    third quarter of 1998. The provision for income taxes was $3.0 million for
    the third quarter of 1999 compared to $2.4 million for the third quarter of
    1998. The Company's effective tax rate is higher than statutory rates
    primarily due to the amortization of the nondeductible portion of goodwill
    associated with certain acquisitions (the tax laws generally permit
    deduction of such expenses for asset purchases, but not for acquisitions of
    stock). In connection with the acquisitions closed in the third quarter of
    1999, the Company recorded approximately $17 million in nondeductible
    goodwill.

    Consolidated income (loss) from continuing operations increased $2.0 million
    to income of $1.0 million (0.7% of consolidated revenues) for the third
    quarter of 1999 from a loss of $1.0 million (1.0% of consolidated revenues)
    for the third quarter of 1998. The loss on the sale of discontinued
    operations is comprised primarily of the write-off of goodwill net of
    applicable taxes.

    As a result of the foregoing factors, consolidated EBITDA from continuing
    operations increased $9.3 million, or 37.4%, to $34.3 million (25.1% of
    consolidated revenues) for the third quarter of 1999 from $25.0 million
    (25.3% of consolidated revenues) for the third quarter of 1998.


    NINE MONTHS ENDED SEPTEMBER 30, 1999 COMPARED TO NINE MONTHS
    ENDED SEPTEMBER 30, 1998

    Consolidated storage revenues increased $62.0 million, or 36.9%, to $230.0
    million for the first nine months of 1999 from $168.0 million for the first
    nine months of 1998. Internal storage revenue growth was 9.9%. The internal
    storage revenue growth resulted primarily from net increases in records and
    other media stored by existing customers and from sales to new customers.

    Consolidated service and storage material sales revenues increased $35.0
    million, or 31.0%, to $148.0 million for the first nine months of 1999 from
    $113.0 million for the first nine months of 1998. Internal service and
    storage material sales revenue growth was 17.0%. The internal revenue growth
    resulted from increases in service and storage material sales to existing
    customers and the addition of new customer accounts.

    For the reasons discussed above, total consolidated revenues increased
    $97.0 million, or 34.5%, to $378.0 million for the first nine months of
    1999 from $281.0 million for the first nine months of 1998.

    Consolidated cost of sales (excluding depreciation) increased $48.6 million,
    or 34.5%, to $189.8 million (50.2% of consolidated revenues) for the first
    nine months of 1999 from $141.2 million (50.2% of consolidated revenues) for
    the first nine months of 1998. The dollar increase was primarily
    attributable to the increase in records and other media stored and expenses
    related to certain facility moves.



                                       19
<PAGE>


                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)

    Consolidated selling, general and administrative expenses increased $24.1
    million, or 34.4%, to $94.2 million (24.9% of consolidated revenues) for the
    first nine months of 1999 from $70.1 million (24.9% of consolidated
    revenues) for the first nine months of 1998. The dollar increase was
    primarily attributable to: (i) the Company's national sales and marketing
    meeting occurring in January 1999; (ii) the adoption of Statement of
    Position 98-1; and (iii) increased personnel, office and overhead costs to
    support the Company's growth.

    Consolidated depreciation and amortization expense increased $10.6 million,
    or 29.8%, to $46.2 million (12.2% of consolidated revenues) for the first
    nine months of 1999 from $35.6 million (12.7% of consolidated revenues) for
    the first nine months of 1998. The dollar increase was primarily
    attributable to the additional depreciation and amortization expense related
    to the 1998 and 1999 Acquisitions, and capital expenditures including
    racking systems, information systems and expansion of storage capacity in
    existing facilities.

    As a result of the foregoing factors, consolidated operating income
    increased $13.6 million, or 39.7%, to $47.8 million (12.7% of consolidated
    revenues) for the first nine months of 1999 from $34.2 million (12.2% of
    consolidated revenues) for the first nine months of 1998.

    Consolidated interest expense increased $6.0 million, or 17.8%, to $40.2
    million for the first nine months of 1999 from $34.2 million for the first
    nine months of 1998. The increase was primarily attributable to increased
    indebtedness related to the financing of acquisitions and capital
    expenditures. The increase was partially offset by lower effective interest
    rates for the first nine months of 1999 compared to the same period in 1998.
    Consolidated other income for the first nine months of 1998 is comprised of
    a $1.7 million gain resulting from the settlement of several insurance
    claims, including a significant claim under its business interruption
    insurance policy, related to the March 1997 fires at the Company's South
    Brunswick Township, New Jersey facilities.

    As a result of the foregoing factors, consolidated income from continuing
    operations before provision for income taxes and minority interest increased
    $5.9 million to $7.7 million (2.0% of consolidated revenues) for the first
    nine months of 1999 from $1.8 million (0.6% of consolidated revenues) for
    the first nine months of 1998. The provision for income taxes was $7.8
    million for the first nine months of 1999 compared to $3.7 million for the
    first nine months of 1998. The Company's effective tax rate is higher than
    statutory rates primarily due to the amortization of the nondeductible
    portion of goodwill associated with certain acquisitions (the tax laws
    generally permit deduction of such expenses for asset purchases, but not for
    acquisitions of stock). In connection with the 1999 Acquisitions, the
    Company recorded approximately $132 million in nondeductible goodwill.

    Consolidated loss from continuing operations decreased $1.4 million to a
    loss of $0.6 million (0.2% of consolidated revenues) for the first nine
    months of 1999 from a loss $2.0 million (0.7% of consolidated revenues) for
    the first nine months of 1998. The loss on the sale of discontinued
    operations is comprised of a $13.1 million write-off of goodwill and $1.3
    million of estimated expenses directly related to the sale of Arcus Staffing
    offset by a $1.0 million deferred tax benefit and the estimated income from
    discontinued operations through the date of disposition.

    As a result of the foregoing factors, consolidated EBITDA from continuing
    operations increased $24.2 million, or 34.7%, to $94.0 million (24.9% of
    consolidated revenues) for the first nine months of 1999 from $69.8 million
    (24.8% of consolidated revenues) for the first nine months of 1998.

                                       20

<PAGE>

                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)


    LIQUIDITY AND CAPITAL RESOURCES

    As the Company has sought to increase its EBITDA, it has made significant
    capital investments, consisting primarily of: (i) acquisitions; (ii) capital
    expenditures, primarily related to growth (including investments in real
    estate, racking systems, information systems and improvements to existing
    facilities); and (iii) customer acquisition costs. Cash paid for these
    investments during the first nine months of 1999 amounted to $187.5 million,
    $72.8 million and $6.1 million, respectively. Included in the $72.8 million
    of capital expenditures is approximately $10 million paid by BDM in
    connection with the acquisition of real estate. In addition, the Company
    advanced $12.0 million to BDM. BDM used the cash to fund a portion of the
    purchase price of its acquisitions of Memogarde, S.A. and Stortext
    (Holdings) Limited. These investments have been primarily funded through
    cash flows from operations, borrowings under the Company's revolving credit
    facility, a portion of the net proceeds from the sale of the 1999 Notes and
    a portion of the net proceeds from the Equity Offering.

    Net cash provided by operations was $29.3 million for the first nine months
    of 1999 compared to $44.7 million for the same period in 1998. The decrease
    resulted primarily from increases in accounts receivable and advances to BDM
    and decreases in accrued expenses and other long-term liabilities, which
    were partially offset by an increase in EBITDA.

    Net cash provided by financing activities was $239.3 million for the nine
    months ended September 30, 1999, consisting primarily of the $303.2 million
    of net proceeds from the sale of the 1999 Notes and the Equity Offering
    offset by the repurchase of the 1,476,577 shares of common stock issued in
    the Data Base acquisition for $39.5 million and $19.7 million net repayment
    of debt.

    On April 26, 1999, the Company completed the sale, in a private placement to
    qualified institutional buyers, of $150 million in aggregate principal
    amount of its 1999 Notes. The 1999 Notes were issued at a price to investors
    of 99.64% of par. On August 25, 1999 the holders of the privately placed
    1999 Notes exchanged them for notes with the same terms as the 1999 Notes,
    except that the new notes were registered under the Securities Act of 1933,
    as amended. The net proceeds from the sale of the 1999 Notes were used to
    repay outstanding indebtedness under the Company's revolving credit
    facility.

    On May 17, 1999, the Company issued and sold an aggregate of 5.8 million
    shares (including approximately 0.8 million shares to cover over-allotments)
    of its Common Stock in an underwritten public offering at a price to the
    public of $28.00 per share. Net proceeds to the Company after deducting
    underwriting discounts and commissions were $153.8 million and were used:
    (i) to repurchase all of the 1,476,577 shares of the Company's Common Stock
    issued in connection with the acquisition of Data Base, Inc. at a purchase
    price of $26.74 per share; (ii) to repay outstanding indebtedness under the
    Company's revolving credit facility; and (iii) for general corporate
    purposes, including the funding of future acquisitions.

    If the contemplated merger with Pierce Leahy Corp. is consummated, the 1996,
    1997 and 1999 Notes, as well as the public debt of Pierce Leahy Corp., will
    remain outstanding as the merger will not result in a "change of control"
    under either company's indentures. The consent of the lenders under the
    Company's existing credit facility is required in connection with the
    Pierce Leahy merger. The Company expects to enter into a new credit
    facility in an amount sufficient to repay indebtedness under the
    Company's and Pierce Leahy's credit facilities and to provide additional
    borrowing capacity after the merger.



                                       21
<PAGE>

                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)

    YEAR 2000 READINESS

    General

    The Year 2000 ("Y2K") problem refers to the inability of systems, primarily
    software systems, to properly recognize and process date sensitive
    information relating to the year 2000 and beyond. In order to respond to
    this problem, the Company has established a Y2K Project Plan (the "Plan").
    The Plan is comprised of five major phases: awareness, assessment,
    renovation, validation and implementation. These phases are applied to three
    general categories: operational systems (consisting primarily of inventory
    and billing systems), financial accounting systems and other products and
    services obtained from third parties.

    Operational Systems

    The Company's primary operational systems are SAFEKEEPER-TM-, an internally
    developed software application used mainly in its business records
    operations, and MEDIALINK-TM-, a software application obtained from a third
    party used mainly in the Company's data security operations. Additionally,
    as an active acquirer of businesses, the Company currently uses, and will
    continue to use, several different legacy operational systems that have
    been, and will be, inherited through its ongoing acquisition program. Both
    SAFEKEEPER and MEDIALINK are Y2K compliant. Based on the Company's
    assessment, management believes that more than 99% of its business units are
    currently operating with an operational system that is Y2K compliant.
    Conversion of the remaining business units to a Y2K compliant operational
    system is currently underway and is expected to be completed before
    year-end.

    Financial Accounting Systems

    As part of its normal course of business, the Company has several system
    improvement initiatives underway, the most significant of which involves the
    installation of new financial accounting software from Oracle Corporation
    ("Oracle"). Oracle has certified that its accounting software is Y2K
    compliant. The installation of the Oracle software is complete.

    The Company currently uses, and will continue to use, several different
    legacy accounting systems that have been, and will be, inherited through its
    ongoing acquisition program. Accordingly, the Company will continue to
    assess legacy systems acquired in future acquisitions. Based on vendor
    certifications, the Company believes that all of the existing legacy systems
    are Y2K compliant.

    Products and Services Obtained from Third Parties

    Products and services obtained from third parties are comprised mainly of
    (i) facility systems, including telecommunications, climate control systems,
    security systems, fire and safety systems ("Facility Systems"), and (ii)
    products and services purchased from vendors, including third party payroll
    processing and products for resale such as cartons and operating supplies.
    The Company has completed the implementation of its remediation plan, in all
    material respects, related to its Facility Systems and products and services
    purchased from vendors.


                                       22
<PAGE>

                           IRON MOUNTAIN INCORPORATED
                     MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                  FINANCIAL CONDITION AND RESULTS OF OPERATIONS

                                  (Continued)

    Customers

    The Company's customer base is diversified in terms of revenue and industry
    concentration. Only two customers account for more than 1% of total revenues
    and no customer accounts for more than 2% of total revenues. Given the
    nature of the services the Company provides to its customers, as well as the
    diversification of its customer base, the Company does not believe that Y2K
    issues associated with its customers will have a material adverse effect on
    its financial condition or results of operations.

    Costs

    Based on the Company's current assessment of its Y2K issues, the total cost
    associated with required modifications to become Y2K compliant is not
    expected to be material to the Company's financial position. Certain costs
    associated with the Company's pre-existing system improvement initiatives
    and the purchase of equipment (including the financial accounting software
    developed by Oracle, SAFEKEEPER and MEDIALINK) will be capitalized and
    amortized over their useful lives. Certain payroll and related costs
    represent the redeployment of existing staff resources rather than
    incremental costs to the Company. All other costs associated with the Plan
    will be expensed as incurred. Costs associated with the Plan to be incurred
    in 1999 are estimated to be under $3 million and are included in the
    Company's operating and capital budgets for 1999.

    Contingency Plans

    As part of its Y2K project, the Company has analyzed its points of major
    risk and has developed contingency plans as a backup to its remediation
    effort. Management continues to review these contingency plans to ensure
    their viability.

    Year 2000 Risks

    The failure on the part of the Company or one of its suppliers to correct a
    material Y2K problem could result in an interruption in, or a failure of,
    certain normal business activities or operations, although the extent of
    such a business disruption is not known at this time. The implementation of
    the Plan has significantly reduced the Company's level of uncertainty about
    the Y2K problem. The Company believes that, with the completion of its
    existing system improvement initiatives and the successful execution of the
    Plan, the likelihood of significant interruptions of normal operations has
    been substantially reduced. However, the Company cannot assure that it has
    been able to address the Y2K issues for all of its software applications and
    major operating systems. If the Company or its major third party suppliers
    of products and services have failed to adequately address their Y2K issues,
    or the Company has failed to successfully integrate or convert its computer
    systems generally, the Company's business, financial condition or results of
     operations could be materially adversely affected.


                                       23
<PAGE>


                        IRON MOUNTAIN INCORPORATED


    ITEM 3 - QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

    The Company does not hold any derivative financial instruments, derivative
    commodity instruments or other financial instruments. The Company's existing
    international operations and any future international investments, if
    completed, may be subject to risks and uncertainties relating to
    fluctuations in currency valuation.

    The Company engages neither in speculative nor derivative trading
    activities. As of September 30, 1999, the Company had $28.2 million of
    variable rate debt outstanding with a weighted average interest rate of
    4.99% and $574.8 million of fixed rate debt. If the weighted average
    variable interest rate had increased by 1% to 5.99%, such increase would
    have had a negative impact on the Company's net income for the three and
    nine month periods ended September 30, 1999 of approximately $59,000 and
    $106,000, respectively. See Note 4 to the Condensed Consolidated Financial
    Statements for a discussion of the Company's long-term indebtedness,
    including the fair values of such indebtedness as of September 30, 1999 and
    December 31, 1998.


PART II - OTHER INFORMATION

ITEM 6 - EXHIBITS AND REPORTS ON FORM 8-K
<TABLE>
<CAPTION>
<S>      <C>           <C>
(a)      EXHIBIT       DESCRIPTION
          10.1         Agency Agreement, dated as of July 1, 1999, by and
                         between Iron Mountain Statutory Trust-1999 and Iron
                         Mountain Records Management, Inc.

          10.2         Lease Agreement, dated as of July 1, 1999, by and
                         between Iron Mountain Statutory Trust-1999 and Iron
                         Mountain Records Management, Inc.

          10.3         Unconditional Guaranty, dated as of July 1, 1999, from
                         Iron Mountain Incorporated to Iron Mountain Statutory
                         Trust-1999

          27.1         Financial Data Schedule for the Nine Months Ended
                         September 30, 1999

          27.2         Financial Data Schedule for the Nine Months Ended
                         September 30, 1998 (Restated)
</TABLE>


    (b)Reports on Form 8-K

       On July 9, 1999, the Company filed a Current Report on Form 8-K to: (i)
       announce its decision to sell Arcus Staffing; (ii) account for the sale
       of Arcus Staffing as a discontinued operation; and (iii) restate certain
       historical financial information to reflect the accounting of the sale as
       a discontinued operation. The Report on Form 8-K also included audited
       financial statements and certain pro forma financial information with
       respect to acquisitions of businesses deemed to be individually
       significant under Rule 3-05 of Regulation S-X.

       On July 29, 1999, the Company filed a Current Report on Form 8-K to
       announce recent amendments to its Second Amended and Restated Credit
       Agreement and to announce its operating results for the three and
       six-month periods ended June 30, 1999.



                                       24
<PAGE>


                           IRON MOUNTAIN INCORPORATED

CERTAIN IMPORTANT FACTORS

This Quarterly Report on Form 10-Q contains statements that constitute
forward looking statements within the meaning of the Securities Exchange Act
of 1934, as amended. These statements appear in a number of places in this
Form 10-Q and include statements regarding the strategies, beliefs or current
expectations of the Company and its management. Readers are cautioned that
any such forward looking statements are not guarantees of future performance
and involve risks and uncertainties, which could cause actual results to
differ materially from those in the forward looking statements. Such factors
include but are not limited to: (i) the Company's ability or inability to
complete the merger of Iron Mountain and Pierce Leahy due to the failure to
obtain necessary regulatory approvals or satisfy other customary conditions,
(ii) failure to fully realize the anticipated cost savings related to the
Pierce Leahy merger in a timely manner because of difficulty in integrating
the operations of the two companies and unanticipated costs as a result of
the merger, (iii) the Company's ability or inability to complete other
acquisitions on satisfactory terms and to integrate acquired companies
efficiently, (iv) the cost and availability of financing for contemplated
growth, (v) the cost and availability of appropriate storage facilities, (vi)
the possibility of a natural disaster or other casualty disrupting operations
to an extent greater than the Company is insured for, (vii) the demand and
price for the Company's services, relative to the cost of providing such
services, (viii) certain risks and uncertainties associated with the
Company's readiness for the year 2000, including but not limited to, the
Company's inability to recruit and/or retain key staff necessary for
addressing year 2000 issues; failure of major third party suppliers of
products and services to adequately address their year 2000 issues despite
assurances to the contrary; delays in the conversion or upgrade of acquired
and to be acquired businesses' software systems to appropriate year 2000
compliant software systems; and actual future costs associated with the
Company's year 2000 plan being greater than currently expected, or (ix) other
trends in competitive or economic conditions affecting the Company's
financial condition or results of operations not presently contemplated. The
information contained in this Form 10-Q and the Company's Annual Report on
Form 10-K for the year ended December 31, 1998, including under the headings
"Business" and "Management's Discussion and Analysis of Financial Condition
and Results of Operations," as revised by the Company's Current Report on
Form 8-K filed with the Securities and Exchange Commission on July 9, 1999,
identifies other important factors that could cause such differences.

                                       25


<PAGE>


                           IRON MOUNTAIN INCORPORATED


                                    SIGNATURE


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.





                                                  IRON MOUNTAIN INCORPORATED



NOVEMBER 12, 1999                                 By:   /S/ JEAN A. BUA
    (date)
                                                  -----------------------------
                                                  Jean A. Bua
                                                  Vice President and
                                                    Corporate Controller
                                                  (Principal Accounting Officer)


                                       26