SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K Current Report Pursuant to Section 13 or 15(d) of The Securities Act of 1934 Date of Report (Date of earliest event reported) JULY 2, 2001 ------------------------------- TETRA TECH, INC. -------------------------------------------------------------------------------- (Exact name of registrant as specified in its charter) DELAWARE 0-19566 95-4148514 -------------------------------------------------------------------------------- (State or other (Commission (I.R.S. Employer jurisdiction File Number) Identification No.) of incorporation) 670 N. ROSEMEAD BOULEVARD, PASADENA, CALIFORNIA 91107-2190 -------------------------------------------------------------------------------- (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code (626) 351-4664 ----------------------------- NOT APPLICABLE -------------------------------------------------------------------------------- (Former name or former address, if changed since last report.) ITEM 5. OTHER EVENTS On July 2, 2001, Tetra Tech, Inc. ("Tetra Tech") announced updated guidance for its third fiscal quarter ended July 1, 2001. Tetra Tech's press release, dated July 2, 2001, titled "Tetra Tech Updates Guidance for Third Quarter Based on Charge for Metricom Work" is attached hereto as Exhibit 99.1. ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS 99.1 Press Release titled "Tetra Tech Updates Guidance for Third Quarter Based on Charge for Metricom Work" dated July 2, 2001. 2 SIGNATURES 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 hereunto duly authorized. Date: July 6, 2001 TETRA TECH, INC. By: /s/ JAMES M. JASKA --------------------------------- James M. Jaska Executive Vice President and Chief Financial Officer 3