Exhibit 2.5

                         LAIDLAW MEDICAL HOLDINGS, INC.

                                 March 25, 2005

Todd Zimmerman
AMR HoldCo, Inc.
6200 S. Syracuse Way, Suite 200
Greenwood Village, CO  80111

Dear Todd:

      Reference is made to each of the Stock Purchase Agreements, dated as of
December 6, 2004, by and among Laidlaw International, Inc. ("Laidlaw"), Laidlaw
Medical Holdings, Inc. ("Seller") and Emergency Medical Services Corporation, as
assigned on January 26, 2005 to AMR HoldCo, Inc. ("Purchaser") and amended on
February 10, 2005 and, with respect to the Stock Purchase Agreement relating to
American Medical Response, Inc., as further amended by the letter agreement
dated March 25, 2005 (collectively, the "Stock Purchase Agreements").
Capitalized terms used but not defined herein have the meanings ascribed thereto
in the Stock Purchase Agreements.

      Concurrently herewith Purchaser is delivering to Seller the sum of
$10,861,000 as an aggregate tentative payment pursuant to Section 1.05(e), net
of the tentative payment pursuant to Section 1.05(i) of the Stock Purchase
Agreements (the "Tentative Payment"). Notwithstanding the provisions of Section
1.05 of the Stock Purchase Agreements, the Tentative Payment shall not be deemed
to be an agreement by Purchaser to the Closing Balance Sheet or the Closing Debt
Schedule prepared by Seller with respect to either Stock Purchase Agreement.
Purchaser shall continue to have the right under Section 1.05(b) of each Stock
Purchase Agreement to deliver a Statement of Objection during the Review Period
and the procedure and payment provisions of Section 1.05 of each Agreement shall
continue to apply; provided, however, that (i) interest accruing under Section
1.05(f) and Section 1.05(i) of each Stock Purchase Agreement will cease to
accrue on the amount of the Tentative Payment as of the date the Tentative
Payment is received by Seller, (ii) Purchaser will be credited (without
duplication) with the amount of the Tentative Payment in the calculation of
amount due to Seller pursuant to Section 1.05 (net of the amount payable by
Seller to Purchaser pursuant to Section 1.05(i) of the Stock Purchase Agreements
and (iii) the amount of the Tentative Payment in excess of amounts payable by
Purchaser to Seller pursuant to Section 1.05 of the Stock Purchase Agreements
shall be repaid to Purchaser within five days after the determination of both
the Final Net Worth Amount and the Excess Debt Amount under the Stock Purchase
Agreements, together with interest at the Applicable Rate from the date Seller
received the Tentative Payment to (and including) the date of payment.

      This letter constitutes an amendment to the Stock Purchase Agreements
solely with respect to the matters contained herein, pursuant to Section 10.03
of each Stock Purchase  Agreement and except as specifically set forth herein,
the terms of the Stock Purchase Agreements shall remain in full force and
effect.



                                             Sincerely,

                                                     /s/   Kevin Benson
                                             -----------------------------------
                                             Kevin Benson
                                             Laidlaw Medical Holdings, Inc.

Accepted and Agreed:

AMR HoldCo, Inc.

By:      /s/  Randy Owen
    --------------------------------
    A duly authorized officer

                      [Signature Page to Amendment Letter]