On December 20, 2002, at 1600 central standard time, a Piper PA-28-180, N3236Y, piloted by a private pilot, was substantially damaged when it impacted trees during a forced landing following a loss of engine power near Osage Beach, Missouri. The airplane was descending to land at the Grand Glaize-Osage Beach Airport (K15), when the power loss occurred. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. Two of the passengers received minor injuries. The pilot and the remaining passenger were not injured. The flight originated from the Sackman Field Airport (H49), Columbia, Illinois, at 1435. The pilot reported that he had filled both fuel tanks prior to his departure from H49. He stated that he encountered strong headwinds and that his ground speed was about 75 knots at 2,400 engine rpm. He stated that he noticed an electrical system failure about 12 to 15 nautical miles (nm) from K15. The pilot did not report the nature of the electrical system failure. He stated that he announced his intention to land at K15 and then switched the master switch off to conserve battery power about 10 nm from K15. The pilot stated that the engine sputtered and quit about 5 to 6 nautical miles from K15. He states that he then turned the master switch and electric fuel pump on and switched to the right fuel tank and the engine started and ran for about 10 to 15 seconds until the battery completely drained and the engine subsequently stopped. The pilot executed a forced landing into a wooded area. The Federal Aviation Administration (FAA) conducted a postaccident examination of the airplane. The right fuel tank contained fuel. No fuel was found in the left fuel tank; however, the fuel tank had been breached due to the impact. No evidence of a fuel spill was found at the accident site. The fuel selector was found positioned for the left fuel tank. The electric fuel pump switch was found in the "ON" position. A mechanic, under the direction of the FAA and National Transportation Safety Board Inspectors, inspected the engine and fuel system subsequent to the removal of the airplane from the accident site. The engine driven fuel pump was removed from the engine and was able to pump fuel from a can when the plunger was moved through its full range. The output side of the fuel pump was then capped and the plunger arm depressed to see if fuel could be forced out of the vent hole. No fuel was observed being forced out of the vent hole. The fuel pump push pin within the engine was checked for operation on the fuel pump lobe and no deficiencies were found. The push pin travel was about one inch. The engine driven fuel pump was re-installed on the engine. Electrical power was supplied to the aircraft electrical system and the electric fuel boost pump was checked for operation. No deficiencies were found with respect to the operation of the electric fuel boost pump. The mechanical fuel pump was again checked for signs of leakage from the vent hole while the electric boost pump was activated and no leakage was detected. The electric fuel pump was switched off, the carburetor drain plug was removed, and the engine was cranked several times using the starter. During engine cranking, no fuel was observed draining from the carburetor drain. The engine exhibited "thumb" compression on all cylinders. The magnetos were checked for operation and re-installed on the engine. At that time, a determination was made not to attempt to start the engine since oil was observed leaking from the engine in the area of the crankshaft seal. The mechanic noted that the only time that fuel was able to be pumped by the engine driven pump was when the pump's plunger was moved through its full range which was greater than the normal travel range of the push pin. A subsequent disassembly of the mechanical fuel pump revealed no apparent deficiencies. No determination was made as to the nature of the electrical system deficiency claimed by the pilot.