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                                                                    Exhibit 10.1

                   This Agreement made as of December 6, 2004

                                 By and Between

                EMSC, Inc., a Delaware corporation ("Purchaser")

                                       and

                       William A. Sanger (the "Executive")

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            WHEREAS, Purchaser desires to purchase all of the issued and
outstanding shares of common stock of (i) EmCare Holdings Inc., a Delaware
corporation and (ii) American Medical Response, Inc., a Delaware corporation
(the "Contemplated Transactions");

            WHEREAS, concurrently with the execution and delivery of this
Agreement, Purchaser will execute that certain (i) Stock Purchase Agreement,
dated as of the date hereof, by and among Laidlaw International, Inc., Laidlaw
Medical Holdings, Inc. and Purchaser (the "AMR Purchase Agreement") and (ii)
Stock Purchase Agreement, dated as of the date hereof, by and among Laidlaw
International, Inc., Laidlaw Medical Holdings, Inc. and Purchaser (the "EmCare
Purchase Agreement" together with the AMR Purchase Agreement, the "Stock
Purchase Agreements");

            WHEREAS, Purchaser desires that the Executive enter into employment
with Purchaser and the Executive desires to be employed by Purchaser.

            NOW THEREFORE, the parties have agreed that the terms and conditions
of the relationship shall be as follows:

                                   ARTICLE 1
                                  DEFINITIONS

            Whenever used in this Agreement, the following terms shall have the
meanings set forth below, and when the meaning is intended, the initial letter
of the word is capitalized:

            (a) "Agreement" means this employment agreement, as amended from
      time to time.

            (b) "AMR" means American Medical Response, Inc., a Delaware
      corporation and a wholly owned subsidiary of Purchaser.

            (c) "Base Salary" means the salary of record paid to the Executive
      as annual salary, and as further indicated in paragraph (a) of Article 4.

            (d) "Board" means the Board of Directors of Purchaser.

            (e) "Cause" means the Executive's:

                  (i) Willful and continued failure to perform substantially the
      Executive's duties with Purchaser or a Subsidiary, which failure is not
      cured within 30 days after Purchaser delivers to the Executive written
      demand for substantial performance, specifically identifying the manner in
      which the Executive has not substantially performed his duties;

                  (ii) Conviction of an indictable offense; or

                  (iii) Willfully engaging in illegal conduct or gross
      misconduct which is materially and demonstrably injurious to Purchaser or
      a Subsidiary.

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      For purposes of this paragraph and Article 12, no act or omission by the
      Executive shall be considered "willful" unless it is done or omitted in
      bad faith or without reasonable belief that the Executive's action or
      omission was in the best interests of Purchaser or a Subsidiary.

            (f) "Committee" means the Compensation Committee of the Board or if
      there is no Compensation Committee, the Board.

            (g) "Effective Date" means the Closing Date (as defined in the Stock
      Purchase Agreements).

            (h) "EmCare" means EmCare Holdings Inc., a Delaware corporation, and
      a wholly owned subsidiary of Purchaser.

            (i) "Executive" means William A. Sanger.

            (j) "15% Internal Rate of Return" means an Investor Return, in cash
      or cash equivalent, at least equal to an amount determined by increasing
      the amount of the initial investment, and all subsequent direct or
      indirect investments by Onex, by the total compounded annual rate of
      return of 15%, taking into account for these purposes the exercise of all
      options to purchase Shares outstanding under the Plan or otherwise
      (including, without limitation, options, other stock awards or interests
      held by affiliates of Onex and their respective employees), which are then
      exercisable or become exercisable as a result of the realization of the
      15% Internal Rate of Return. Whether the 15% Internal Rate of Return has
      been realized shall be determined by the Board whose decision shall be
      final and binding on the Executive. For the avoidance of doubt, a 15%
      Internal Rate of Return shall be deemed realized only if the Investor
      Return includes both the amount of the investments and the required return
      on the investments.

            (k) "Investor Return" means the sum of all cash amounts actually
      received by Onex, on a cumulative basis through the date of determination,
      in the form of cash dividends, other distributions or sale proceeds in
      connection with (a) a disposition of all or any part of its Shares
      calculated based on the actual net proceeds received from the disposition
      of such Shares, (b) a disposition of all or substantially all of the
      assets of Purchaser or a Subsidiary or (c) a recapitalization of Purchaser
      or any Subsidiary. Such calculation shall take into account any
      transaction costs and fees and shall exclude any management, consulting or
      other similar fees received by Onex or its affiliates.

            (l) "IPO/Recap" means an initial public offering of the equity of
      Purchaser (an "IPO") or a recapitalization of the Purchaser.

            (m) "Liquidity Event" means (i) the sale of all, or substantially
      all, of Purchaser's consolidated assets, including, without limitation, a
      sale of all or substantially all of the assets of Purchaser or any of its
      Subsidiaries whose assets constitute all or substantially all of
      Purchaser's consolidated assets in any single transaction or series of
      related transactions or (ii) any merger or consolidation of Purchaser with
      or into another

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      corporation unless, after giving effect to such merger or consolidation,
      the holders of Purchaser's voting securities (on a fully-diluted basis)
      immediately prior to the merger or consolidation, own voting securities
      (on a fully-diluted basis) of the surviving or resulting corporation
      representing a majority of the outstanding voting power to elect directors
      of the surviving or resulting corporation in the same proportions that
      they held their shares prior to such merger.

            (n) "Onex" means Onex Partners LP.

            (o) "Purchaser" means EMSC, Inc., a corporation incorporated under
      the laws of Delaware, and except where the context requires otherwise,
      including all affiliates and Subsidiaries of Purchaser, and any successor
      thereto.

            (p) "Shares" means shares of the common stock of Purchaser.

            (q) "Subsidiary" means any corporation that is a subsidiary of
      Purchaser, including but not limited to EmCare and AMR.

            (r) "Change in ownership or control" means, during the Term, the
      sale of all or substantially all of the assets of the Company.

                                   ARTICLE 2
                             TERM OF THE AGREEMENT

            This Agreement shall commence on the Effective Date and shall
continue for a period of five years unless earlier terminated in accordance with
Article 6 hereof.

                                   ARTICLE 3
                  TITLE; COMMENCEMENT OF EMPLOYMENT; REPORTING

            The Executive shall serve as the Chairman and Chief Executive
Officer of Purchaser, and, at Purchaser's request, as President and Chief
Executive Officer of a Subsidiary. The Executive's employment shall commence on
the Effective Date. The Executive shall report to the Board.

                                   ARTICLE 4
                                  COMPENSATION

            (a) Unless otherwise provided, all dollar amounts set forth in this
Agreement shall be in United States Dollars. The Base Salary of the Executive
for his services shall be at the annualized rate of $850,000. The Base Salary
shall be payable twice monthly on the 15th business day and last business day of
each month. The Base Salary shall be reviewed annually beginning in the year
following the second anniversary of the Effective Date during Purchaser's normal
review period. The review will be undertaken by assessing the Executive's
achievement of the overall objectives established by the Committee in
consultation with the Executive and with regard to the market rates of
remuneration paid for similar duties and responsibilities.

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            (b) The Executive will be eligible to participate in a short term
incentive plan. For fiscal years commencing September 1, 2004 and thereafter,
the Executive's target bonus under such plan will be 100% of Base Salary
(prorated for a partial fiscal year, including the first fiscal year in the
term). The Executive's right to receive any bonus under such plan shall be
determined based upon performance targets for each fiscal year fixed by the
Board or the Committee during the first quarter of the year; provided, that in
the case of the partial fiscal year beginning on the Effective Date the
Executive's right to receive any bonus under such plan shall be based on the
achievement of the budget/business plan of EmCare and AMR for the fiscal year
ending August 31, 2005 approved by the board of directors of Laidlaw
International, Inc.

            (c) Purchaser will adopt a stock option plan (the "Plan") to be
effective as of the Effective Date. Pursuant to the Plan, Purchaser will grant
to the Executive, as of the Effective Date, options to purchase four percent
(4%) of the Shares outstanding on the Effective Date (the "Sanger Options"). The
Sanger Options will contain the following terms and will otherwise be subject to
the terms and provisions of the Plan:

                  (i) Exercise Price. The exercise price will be the per share
      purchase price paid by the initial equity investors in Purchaser.

                  (ii) Vesting and Exercisability.

                        (I) 50% of the Sanger Options will become vested and
      exercisable 12.5% on each of the first eight sixth-month anniversaries of
      the Effective Date without further condition. In the event Sanger is
      terminated as provided in this Agreement, the Sanger Options shall vest
      and be exercisable as if Sanger had remained employed up to the nearest
      six-month anniversary.

                        (II) 50% of the Sanger Options will become vested and
      exercisable 12.5% on each of the first eight sixth-month anniversaries of
      the Effective Date, provided, that exercisability is subject to the
      further condition that Onex has realized a 15% Internal Rate of Return. In
      the event Sanger is terminated as provided in this Agreement, the Sanger
      Options shall vest and be exercisable as if Sanger had remained employed
      up to the nearest sixth-month anniversary; provided, that exercisability
      is subject to the further condition that Onex has realized a 15% Internal
      Rate of Return.

                        (III) Notwithstanding the provisions of clause (II),
      upon the occurrence of a Liquidity Event in which Onex realizes a 15%
      Internal Rate of Return, all of the Sanger Options shall become fully
      vested and exercisable on the occurrence of the Liquidity Event, and the
      Sanger Options shall terminate and be of no further force or effect if
      they are not exercised in connection with the Liquidity Event. For the
      purposes of this clause (III) only, the 15% Internal Rate of Return shall
      be determined based on (i) cash received by Onex at any time and/or (ii)
      the fair market value of assets received by Onex at any time (as such fair
      market value is determined by the Board). Any assets received by the
      Executive in the Liquidity Event shall be subject to the same restrictions
      (such as lock-up provisions) to which the assets received by Onex are
      subject.

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                        (IV) On the fourth anniversary of the Effective Date, if
      the Sanger Options referred to in clause (II) have not terminated pursuant
      to clause (III) and have vested but are not exercisable because Onex has
      not realized a 15% Internal Rate of Return, then such Sanger Options shall
      also become exercisable if:

                              (a) Purchaser has met the Cumulative Cash Flow
      Test, as such term will be defined in the Plan, or

                              (b) if (x) Purchaser's common stock is publicly
      traded and listed on a national securities exchange and (y) Onex would
      have realized a 15% Internal Rate of Return if it had sold its remaining
      common stock interest in Purchaser at a per share price equal to the
      weighted average sale price of the Purchaser common stock (as quoted by
      such national securities exchange) for any 30 consecutive trading days.

                  (iii) Term. For the avoidance of doubt, Options that have
      vested (by acceleration or otherwise) upon the occurrence of a Liquidity
      Event but are not exercisable because Onex has not realized a 15% Internal
      Rate of Return shall terminate on the occurrence of the Liquidity Event,
      and be of no further force or effect. The occurrence of an IPO/Recap shall
      not affect the vesting of the Sanger Options.

                                   ARTICLE 5
                                    BENEFITS

            (a) AUTOMOBILE

            Purchaser will, or will cause a Subsidiary to, (i) provide the
Executive with a monthly allowance of $1,200 for expenses incurred by the
Executive for the leasing of an automobile and (ii) reimburse the Executive for
expenses incurred by the Executive in connection with the related operating and
insurance expenses for such automobile, provided that the Executive provides an
itemized written account and receipts acceptable to Purchaser.

            (b) EXPENSES

            It is understood and agreed that the Executive will incur expenses
in connection with his duties under this Agreement, including, but not limited
to, travel expenses, home facsimile expenses, personal computer expenses and
telephone expenses. Purchaser shall, or shall cause a Subsidiary to, reimburse
the Executive for any such expenses provided that the Executive provides an
itemized written account and receipts acceptable to Purchaser.

            (c) VACATION

            The Executive shall be entitled to five weeks vacation during each
calendar year, prorated, however for 2005 based on the number of days remaining
in 2005 after the date of this Agreement divided by 365. The vacation shall be
taken at the discretion of the Executive with the understanding that the
Executive will take into account business needs and operations in scheduling
vacation. Any vacation not used in a given year shall be paid or carried forward
at Sanger's option.

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            (d) WELFARE BENEFITS

            Purchaser shall, or shall cause a Subsidiary to, provide to the
Executive welfare benefit coverages (such as medical insurance, dental
insurance, short and long-term disability insurance and group term life
insurance) in accordance with employee benefit plans and policies maintained by
Purchaser or a Subsidiary for the benefit of its employees of Purchaser, and as
amended from time to time; provided, however, that Purchaser shall, or shall
cause a Subsidiary to, reimburse the Executive for premiums paid by the
Executive, if any, for coverage under such employee benefit plans and policies.
Further, Purchaser shall, or shall cause a Subsidiary to, provide the Executive
with additional term life insurance that, in conjunction with coverage under the
group life insurance programs provided to the Executive, provides coverage in an
amount equal to five times the Executive's Base Salary.

            (e) EXECUTIVE HOUSING ALLOWANCE

            Until the earlier of the date that is 18 months from the Effective
Date or the date of the termination of this Agreement (the "Rental Period"),
Purchaser shall allow the Executive to reside at the residence owned by AMR and
located at 430 Steele Street, Denver, Colorado (the "Residence"). While the
Executive resides in the Residence, the Executive shall make a monthly rental
payment to AMR in an amount equal to $4,200. During the Rental Period and for a
period of one month thereafter, the Executive shall have the option, upon at
least 30 days advance written notice to AMR, to purchase the Residence from AMR
for an amount equal to the fair market value of the Residence (as determined by
an independent appraiser) on the date on which the Executive purchases the
Residence pursuant to such option, reduced by the value on such date of any
leasehold improvements made to the Residence by the Executive. If the Executive
does not exercise his option to purchase the Residence pursuant to the preceding
sentence, AMR shall reimburse the Executive for the value of any leasehold
improvements made to the Residence by the Executive. Additionally, The Executive
shall be entitled to reimbursement of customary moving and transportation
expenses in connection with the Executive's relocation to Denver, Colorado. AMR
or EmCare will reimburse Executive for the cost of the commercial airfare for
one trip to Delray Beach per month by the Executive and his spouse until the
earlier of (x) the sale of Executive's home in Delray Beach, Florida or (y)
October 1, 2005, and AMR or EmCare shall reimburse the Executive for ordinary
and reasonable closing costs (excluding realty fees) with respect to the sale of
his home in Delray Beach, Florida.

                                   ARTICLE 6
                            TERMINATION OF EMPLOYMENT

            (a) Notwithstanding the provisions of Article 2 of this Agreement,
the parties understand and agree that this Agreement and the Executive's
employment hereunder may be terminated in the following manner in the specified
circumstances:

                  (i) By the Executive, at any time, for any reason, on the
      giving of 90 days' written notice to Purchaser. Purchaser may waive
      notice, in whole or in part, upon immediate payment to the Executive of
      the Executive's Base Salary for such portion of the 90-day notice period
      as is waived by Purchaser. Upon such termination, Purchaser may elect, in
      its sole and absolute discretion, to pay the Executive his Base Salary in

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      effect at the time of such termination for a period of 24 months following
      such termination as consideration for Executive's agreement set forth in
      paragraphs (b) and (c) of this Article 6.

                  (ii) By Purchaser, without any notice or pay, for Cause.

                  (iii) By Purchaser, in its absolute discretion and for any
      reason, without Cause. Upon such termination, Purchaser shall (A) continue
      to pay the Executive his Base Salary in effect at the time of such
      termination for a period of 24 months following such termination, (B)
      continue to provide the Executive medical insurance, dental insurance and
      term life insurance (but excluding the life insurance referred to in the
      last sentence of paragraph (d) in Article 5) during the applicable
      termination period, or, if such benefits cannot be provided, Purchaser
      shall, or shall cause a Subsidiary to, pay to the Executive an equivalent
      lump sum cash amount in lieu of such benefits. In the event of a
      termination under this section, all time - governed Sanger Options shall
      vest and be exercisable as and to the extent provided in Article 4.

                  (iv) The Executive may terminate employment with the Company
      and any Subsidiary with the right to severance compensation as provided in
      Article 6(a)(iii) upon the occurrence of a Change in Control followed by
      one or more of the following events:

                  (A)   Failure to elect or reelect or otherwise to maintain the
                        Executive in the office or position, or a substantially
                        equivalent office or position, of or with the Company
                        which the Executive held immediately prior to the Change
                        in Control;

                  (B)   (1) A significant adverse change in the nature or scope
                        of the authorities, powers, functions, responsibilities
                        or duties attached to the position with the Company
                        which the Executive held immediately prior to the Change
                        in Control, (2) a reduction in the aggregate of the
                        Executive's Base Pay received from the Company or the
                        value of the Executive's incentive pay opportunity from
                        the Company or its Subsidiaries, or (3) the termination
                        of the Executive's rights to employee benefits or a
                        reduction in the scope or value thereof to a level that
                        is substantially lower in the aggregate from the level
                        in effect at the time of the Change in Control, any of
                        which is not remedied by the Company with 10 calendar
                        days after receipt by the Company of written notice from
                        the Executive of such change, reduction, or termination,
                        as the case may be;

                  (C)   The liquidation, dissolution, merger, consolidation or
                        reorganization of the Company or transfer of all or
                        substantially all of its business and/or assets, unless
                        the successor or successors (by liquidation, merger,
                        consolidation, reorganization, transfer or otherwise) to
                        which all or substantially all of its business and/or
                        assets have been

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                        transferred (by operation of law or otherwise) assumed
                        all duties and obligations of the Company.

            In order to receive the entitlement under paragraphs 6(a)(i) and
6(a)(iii), the Executive must undertake to sign a release in a form satisfactory
to Purchaser, fully releasing Purchaser, from further claims upon payment of the
amounts stipulated herein. However, the form of release shall not require that
the Executive give up any rights of indemnity which the Executive may have had
as against Purchaser for acts carried out by the Executive in the ordinary
course of Purchaser's business.

            (b) The Executive agrees that during employment pursuant to this
Agreement and for 24 months following termination of his employment and during
payment of the severance payment amount and benefit continuation, if applicable,
as detailed in subparagraphs (i) and (iii) of paragraph (a) of this Article 6,
he will not compete, solicit or accept business with respect to products
competitive with those of Purchaser from any of Purchaser's customers, wherever
situated, and he shall not either individually or in partnership, or jointly in
conjunction with any other person, entity or organization, as principal, agent,
consultant, lender, contractor, employer, employee, investor, shareholder, or in
any other manner, directly or indirectly, advise, manage, carry on, establish,
control, engage in, invest in, offer financial assistance or services to, or
permit his name to be used by any business that competes with the then-existing
business of Purchaser or any Subsidiary, provided that the Executive shall be
entitled, for investment purposes, to purchase and trade shares of a public
company which are listed and posted for trading on a recognized stock exchange
and the business of which public company may be in competition with the business
of Purchaser or any Subsidiary, provided that the Executive shall not directly
or indirectly own more than five percent (5%) of the issued share capital of the
public company, or participate in its management or operation, or in any
advisory capacity within the time limits set out herein.

            For purposes of the obligations set out herein, the business of
Purchaser shall mean the provision of (a) critical care transportation services,
non-emergency ambulance and transfer services and emergency response services
and/or (b) emergency management services to hospital-based emergency departments
and freestanding emergency clinics and (c) inpatient hospitalist services.

            (c) The Executive further agrees that for a period of 24 months
following termination of employment, however caused, he will not solicit for
hire or rehire, or take away, or cause to be hired, or taken away, employee(s)
of Purchaser.

                                   ARTICLE 7
                                   AUTHORITY

            (a) The Executive shall have, subject always to the general or
specific instructions and directions of the Board, full power and authority to
manage and direct the business affairs of Purchaser (except only the matters and
duties as by law must be transacted or performed by the Board or by the
shareholders of Purchaser or a Subsidiary), including power and authority to
enter into contracts, engagements or commitments of every nature or kind, in the
name of and on behalf of Purchaser or a Subsidiary which the Executive is
President and to engage, employ and

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dismiss all managers and other employees and agents of such Subsidiary, subject
to the by-laws and charter documents of Purchaser or the respective Subsidiary.

            (b) The Executive shall conform to all lawful instructions and
directions given to him by the Board and the board of directors of each
Subsidiary and obey and carry out the by-laws of Purchaser and each Subsidiary.

                                   ARTICLE 8
                                    SERVICE

            (a) The Executive, throughout the term of his employment, shall
devote his full time and attention to the business and affairs of Purchaser and
shall not undertake any other business or occupation or, unless approved by the
Board, become either (i) an officer, employee or agent of any other company or
firm which is a commercial venture or (ii) a director of more than two companies
or firms which are commercial ventures; provided, however, that the Executive
shall be entitled to maintain his ownership interest in BIDON Inc. ("BIDON") and
shall be entitled to attend the meetings of the principals of BIDON from time to
time, provided that such ownership or attendance does not conflict with the
Executive's duties and obligations hereunder.

            (b) The Executive shall well and faithfully serve Purchaser and use
his best efforts to promote the interests thereof and shall not disclose any
information he may acquire in relation to Purchaser's business, the private
affairs or trade secrets of Purchaser, techniques and concepts, and other
confidential information concerning the business, operations or financing of
Purchaser to any person other than the Board, or for any purposes other than
those of Purchaser either during the term of his employment under this Agreement
or after such term.

                                    ARTICLE 9
                              ASSIGNMENT OF RIGHTS

            The rights which accrue to Purchaser or any Subsidiary under this
Agreement shall pass to their affiliates, successors or assigns. The rights of
the Executive under this Agreement are not assignable or transferable in any
manner but flow to the Executive's estate and heirs.

                                   ARTICLE 10
                                     NOTICES

            All notices and other communications required or permitted
hereunder, or necessary or convenient in connection herewith, shall be in
writing and shall be deemed to have been given when hand delivered, delivered by
facsimile or mailed by registered mail as follows (provided that notice of
change of address shall be deemed given only when received):

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            If to Purchaser:

               EMSC, Inc.
               c/o Onex Investment Corporation
               New York, New York 10019
               Attention:  Robert M. Le Blanc, President
               Facsimile: (212) 582-0909

            If to the Executive, to:

               William A. Sanger
               430 Steele Street
               Denver, Colorado

            or to such other names or addresses as Purchaser or the Executive
            shall designate by notice to the other in the manner specified in
            this paragraph.

                                   ARTICLE 11
                               LIABILITY INSURANCE

            Purchaser shall, or shall cause one or more Subsidiaries to,
maintain the Executive's liability insurance in accordance with corporate policy
and applicable law.

                                   ARTICLE 12
                                 INDEMNIFICATION

            Purchaser shall, or shall cause a Subsidiary to, agree that if the
Executive is made a party to any action, suit, proceeding or any other claim
whatsoever, by reason of the fact that the Executive is or was a director,
officer, employee or agent of Purchaser and one or more Subsidiaries, or is or
was serving at the request of Purchaser and one or more Subsidiaries, as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, whether or not the basis of such claim is
the Executive's alleged action in an official capacity while in service as a
director, officer, employee or agent of Purchaser and one or more Subsidiaries
the Executive shall be indemnified and held harmless by Purchaser and one or
more Subsidiaries to the fullest extent legally permitted or authorized by
Purchaser's and such Subsidiaries' certificate of incorporation or bylaws or
resolutions of the Board against all expenses, liability and loss, including,
without limitation, legal fees, fines or penalties and amounts paid or to be
paid in settlement, all as reasonably incurred by the Executive in connection
therewith, and such indemnification shall continue as to the Executive even
after the Executive has ceased to be a director, officer, employee or agent of
Purchaser such Subsidiaries, and shall inure to the benefit of the Executive's
heirs, executors and administrators.

                                   ARTICLE 13
                                   TERMINATION

            If the Contemplated Transactions are not consummated on or before
March 31, 2005 this Agreement will automatically terminate and be void ab
initio.

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                                   ARTICLE 14
                              WITHHOLDING OF TAXES

            Purchaser shall, or shall cause a Subsidiary to, withhold from any
amounts payable under this Agreement all taxes as legally shall be required
pursuant to applicable federal, state or local laws. Neither Purchaser nor any
Subsidiary will be obligated to compensate the Executive for the payment of such
taxes.

                                   ARTICLE 15
                                  SEVERABILITY

            If any provision of this Agreement or the application thereof to
anyone, or under any circumstances, is adjudicated to be invalid or
unenforceable in any jurisdiction, such invalidity or unenforceability shall not
affect any other provision or application of this Agreement which can be given
effect without the invalid or unenforceable provision or application and shall
not invalidate or render unenforceable such provision or application in any
other jurisdiction.

                                   ARTICLE 16
                                ENTIRE AGREEMENT

            This Agreement constitutes the entire agreement between the parties
with respect to the employment and appointment of the Executive and any and all
previous agreements, written or oral, express or implied, between the parties or
on their behalf, relating to the employment and appointment of the Executive by
Purchaser or any Subsidiary, are terminated and cancelled and each of the
parties releases and forever discharges the other of and from all manner of
actions, causes of action, claims and demands whatsoever, under or in respect of
any previous agreement, without limitation, the (i) Agreement, effective October
1, 2002, by and among Laidlaw Inc., AMR, EmCare and the Executive and (ii)
Change in Control Severance Agreement, between AMR and the Executive, are hereby
terminated and cancelled.

                                   ARTICLE 17
                             AMENDMENT, WAIVER, ETC.

            No provision of this Agreement may be modified, waived or discharged
unless such waiver, modification or discharge is agreed to in writing and signed
by the Executive and Purchaser. No waiver by any party hereto at any time of any
breach by any other party hereto of, or compliance with, any condition of this
Agreement to be performed by such other party shall be deemed a waiver of
similar or dissimilar provisions or conditions at the same or at any prior or
subsequent time.

                                   ARTICLE 18
                                    HEADINGS

            The headings used in this Agreement are for convenience only and are
not to be construed in any way as additions to or limitations of the covenants
and agreements contained in it.

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                                   ARTICLE 19
                                  COUNTERPARTS

            This Agreement may be executed in one or more counterparts, each of
which shall be deemed to be an original but all of which together will
constitute one and the same instrument.

                                   ARTICLE 20
                                GENDER AND NUMBER

            Except where otherwise indicated by the context, any masculine term
used herein shall also include the feminine; the plural shall include the
singular, the singular shall include the plural.

                                   ARTICLE 21

                               ADDITIONAL EXPENSES

            Purchaser shall reimburse Sanger up to $10,000 for costs associated
with entering into a new agreement. These costs are limited to legal and advisor
costs.

                                   ARTICLE 22
                                  GOVERNING LAW

            This Agreement shall be governed by the internal law, and not the
laws of conflicts, of the State of Delaware.

                           [SIGNATURES ON NEXT PAGE.]

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            IN WITNESS WHEREOF, the parties have executed this Agreement on the
6th day of December 2004

                                                  EMSC, Inc.

                                                  By: /s/ Robert M. Le Blanc
                                                      --------------------------
                                                  Name: Robert M. Le Blanc
                                                  Title: President

                                                  /s/ William A Sanger
                                                  ------------------------------
                                                  William A. Sanger

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