On March 9, 2003, approximately 1530 central standard time, a Cessna 150K single-engine airplane, N6066G, sustained substantial damage during a forced landing to a pasture following a loss of engine power during the approach to the Sherman Municipal Airport (SWI) near Sherman, Texas. The flight instructor and student pilot were not injured. The airplane was registered to and operated by the student pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 instructional flight. The local flight departed the Aero Country Airport (TX05), McKinney, Texas, at 1520, with a planned fuel stop at SWI. The student pilot reported that prior to the flight, he preflighted the airplane, in which he checked the fuel tanks with a measuring stick. He determined that the right tank contained approximately 1" of fuel, the left tank contained approximately 1 1/4" of fuel, which equated to approximately 7 1/2 gallons, or 1 hour and 15 mintues of fuel. The flight instructor reported that when he arrived at the airport, the student pilot had already completed the airplane preflight. Subsequently, the flight instructor did not preflight the airplane; however, "quizzed [the student pilot] on fuel and oil quantities." The flight instructor and student pilot then decided that they would stop at SWI for fuel, before continuning with the instructional flight (SWI is located 26 nautical miles north-northwest of TX05). TX05 did not have fuel service available. The flight instructor added that the engine run-up and departure were normal. Approximately 20 minutes into the flight, 3 miles south of SWI, and at 1,500 feet agl, the engine lost total power. Subsequently, the flight instructor initiated a forced landing to a field. During the forced landing, the airplane struck a culvert and came to rest upright. According to an FAA inspector, who responded to the accident site, the firewall was buckled, the nose and right main landing gear were separated. No evidence of fuel was found in the fuel tanks.