On August 29, 2002, about 1715 eastern daylight time, a Cessna 150, N60425, was substantially damaged during a forced landing at the Louisa County Airport, Louisa, Virginia. The certificated flight instructor sustained serious injuries, and the student pilot sustained minor injuries. Visual meteorological conditions prevailed for the local instructional flight. A flight plan was not filed, and the flight was conducted under 14 CFR Part 91. According to the instructor, he met with the student about 1700. They preflighted the airplane together, noted no anomalies, and then boarded. The engine started on the first attempt, and the student taxied the airplane short of runway 27, where the engine runup checks were completed. No anomalies were noted, and after about a 5-minute delay, the student taxied the airplane onto the runway. The student applied full power, the engine responded, and the airplane accelerated as expected. When the airspeed indicator reached approximately 65 mph, the airplane lifted off. After climbing through approximately 50 feet agl, the engine suddenly lost all power. The instructor took the controls, set the airplane back down onto the runway, and applied maximum braking. The airplane overran the end of the runway, impacted a small ditch that was concealed by grass, nosed over, and came to a stop. The instructor and student then exited. About 2 minutes later, the instructor collapsed, and was medivaced to a local hospital. According to a Federal Aviation Administration (FAA) inspector, the left fuel tank contained approximately 5 gallons of fuel, the right contained approximately 6 gallons, no contaminants were identified in the fuel system, and the fuel selector was in the "OFF" position. Examination of the sparkplug electrodes revealed they were gray in color and absent of debris. During the examination, no preimpact failures or malfunctions were identified. In addition, a witness reported that the fuel selector was moved by rescue personnel. With the engine on the accident airplane, three different engine runs were performed on September 13, 2002. During the first run, the engine started, and ran for approximately 1 minute before being shut down because of a low oil pressure indication. A broken oil pressure indication line was identified and replaced. The second engine run lasted about 5 minutes, and was limited to 1,200 rpm because of propeller damage. The third engine run also lasted about 5 minutes, was limited to 1,200 rpm, and a magneto check was performed. Once again, no anomalies were noted, and the engine was shutdown.