On May 15, 2003, about 1940 eastern daylight time, a homebuilt Rans S9, N93WD, registered to and operated by a private individual, collided with trees then the ground following a loss of engine power shortly after takeoff from Haller Airpark, Green Cove Springs, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the commercial rated pilot, the sole occupant, sustained serious injuries. The flight was originating at the time of the accident. The pilot stated that he performed a normal preflight and started the engine per the checklist. He performed an engine run-up before takeoff which included checking the magnetos; no discrepancies were reported. The flight departed from runway 18 with 8 gallons of automotive fuel, and at approximately 250 feet , the engine failed. The airplane crashed into a tree line, and after coming to rest, he evacuated the airplane and crawled to safety. According to an FAA inspector who examined the airplane and accident site area, a witness reported observing the airplane take off from runway 18, and when the flight was approximately 200 feet above ground level during the upwind leg, he heard the engine experience a loss of power. The airplane was observed to bank to the left and continued the turn. The witness lost sight of the airplane due to obstructions and reported hearing the accident. Examination of the accident site by the FAA inspector revealed the airplane descended nearly vertically and came to rest upright in a wooded area. Both wing fuel tanks were breached; the smell of fuel was noted. The propeller was rotated by hand revealing the engine was not seized. Impact damage to the ignition system and fuel injector precluded operation of the engine or bench testing of the components. Examination of the flight controls revealed no evidence of preimpact failure or malfunction.