SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 SCHEDULE 13D/A
                    Under the Securities Exchange Act of 1934
                               (Amendment No. 24)

                              Quanta Services, Inc.
                              ---------------------
                                (Name of Issuer)

                        Common Stock, $0.00001 par value
                        --------------------------------
                         (Title of Class of Securities)

                                    74762E102
                                    ---------
                                 (CUSIP Number)

       Leslie J. Parrette, Jr., Senior Vice President, General Counsel and
       -------------------------------------------------------------------
                              Corporate Secretary
                              -------------------
              Acquila, Inc. (formerly, UtiliCorp United Inc.)
              -----------------------------------------------
        20 West Ninth Street, Kansas City, Missouri 64105 (816) 421-6600
        ----------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                  March 21, 2002
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f), or 13d-1(g), check the following
box. / /

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Section 240.13d-7(b) for
other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



                               AMENDMENT NO. 24 TO
                            STATEMENT ON SCHEDULE 13D

INTRODUCTION

     All information herein with respect to Aquila, Inc. (formerly known as
UtiliCorp United Inc.), a Delaware corporation ("Aquila"), and the common
stock, par value $0.00001 per share (the "Common Stock"), of Quanta
Services, Inc., a Delaware corporation ("Issuer" or "Quanta"), is correct to
the best knowledge and belief of Aquila. The Schedule 13D originally filed on
October 4, 1999 on behalf of Aquila and twenty-three amendments thereto filed
on October 8, 1999, October 14, 1999, October 20, 1999, October 26, 1999,
November 9, 1999, January 13, 2000, April 27, 2000, May 25, 2000, June 20,
2000, July 17, 2000, May 23, 2001, October 1, 2001, October 4, 2001, October
11, 2001, October 19, 2001, October 30, 2001, November 13, 2001, November 28,
2001, February 8, 2002, February 25, 2002, March 7, 2002 and March 12, 2002
respectively, on behalf of Aquila are incorporated by reference and amended
as follows.

ITEM 4. PURPOSE OF TRANSACTION.

     On March 21, 2002, Aquila filed a complaint and a motion for an
expedited hearing in Delaware Chancery Court against Quanta and certain
Quanta directors seeking to prevent the implementation and operation of
Quanta's newly adopted Stock Employee Compensation Trust (the "SECT"). The
complaint as well as a press release announcing the filing are attached
hereto as exhibits.

                                       2


ITEM 7.           MATERIAL TO BE FILED AS EXHIBITS.

Complaint filed by Aquila against Quanta in the Court of Chancery of the
State of Delaware in and for New Castle County on March 21, 2002.

Aquila Press Release dated March 21, 2002.

                                       3



                                    SIGNATURE

     After reasonable inquiry and to the best of the undersigned's knowledge and
belief, the undersigned hereby certifies that the information set forth in this
statement is true, complete and correct.

Dated: March 21, 2002                Aquila, Inc.

                                        By:       /s/ Leslie J. Parrette, Jr.
                                        Name:     Leslie J. Parrette, Jr.
                                        Title:    Senior Vice President,
                                                  General Counsel and Corporate
                                                  Secretary


                                       4