On September 2, 1995, at 1152 eastern daylight time, a Cessna 152, N211SP, experienced a loss of engine power while on approach to the Roanoke Regional Airport, Roanoke, VA. The airplane was destroyed during the emergency landing. The pilot received minor injuries. An instrument flight plan had been filed and activated. Visual meteorological conditions prevailed and the flight was conducted under 14 CFR Part 91. The flight originated from Jefferson/Jackson County Airport, Jefferson, Georgia, at approximately 0835 eastern daylight time. The pilot stated that the airplane's fuel tanks were filled the previous evening. The pilot reported that she then flew the airplane for 4 tenths of an hour doing touch and go landings. The pilot stated that during the preflight inspection the next morning, the fuel tanks appeared full and no one had flown the airplane after her flight the previous evening. The pilot stated that it was her understanding that the accident airplane had the capability of four hours of flight. She reported that the airplane's fuel tanks held 24.5 gallons of usable fuel and the fuel consumption rate was approximately 6 gallons per hour. The pilot subtracted the .4 hour flown the evening prior and calculated that there should have been approximately 3.6 hours of fuel onboard. The pilot concluded there was plenty of fuel for the planned 2 hour and 40 minute flight to Roanoke, Virginia. The Piper Cherokee 140 that the pilot normally flew, was not available for this trip. The pilot stated that she had not flown in the accident make/model airplane for some time, and was not familiar with the fuel mixture leaning procedures in the accident airplane. The instrument rated pilot stated that during the flight she calculated her ground speed as less than what she had planned. She also reported that vectors around traffic and other delays she encountered while en route on an IFR flight plan extended her flight time. About three hours and fifteen minutes after takeoff, when the airplane was approximately 10 miles from the destination airport, the airplane's engine lost power. The pilot stated the engine restarted briefly during the emergency descent, then stopped again. The pilot made a forced landing in a soft hayfield. During the landing roll, the nose gear collapsed and the airplane nosed over. Posaccident examination of the aircraft revealed no evidence of preimpact mechanical malfunction, and no usable fuel in either of the fuel tanks. Examination of the accident site revealed no evidence of aviation fuel spillage.