On October 19, 2004, at 1716 central daylight time, a Cessna 150L single-engine airplane, N6870G, was substantially damaged during a forced landing following a reported loss of engine power during takeoff initial climb from the Denton Municipal Airport, near Denton, Texas. The flight instructor and student pilot were not injured. The airplane was registered to and operated by a private individual. 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 originated at 1700. The 2,292-hour flight instructor reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that after completing four touch-and-go landings, "the engine lost power," approximately 300 feet above ground level (agl) at the departure end of runway 17. The flight instructor initiated a forced landing to a field, approximately 1,000 feet from the airport property. Subsequently, the left wing of the airplane impacted a tree as the airplane came to rest upright. Examination of the airplane by an Federal Aviation Administration (FAA) inspector, who responded to the accident site, revealed that both wings were bent, and the empennage aft of the cabin area was bent approximately 90 degrees to the left. Review of the airplane maintenance records revealed the airplane completed its most recent annual inspection on October 14, 2004, with an engine time of 1,414.87 hours since major overhaul. At the time of the accident, the engine had accumulated 1,775.94 hours since the major overhaul, with an engine total time of 5,357.04 hours. A log book entry dated July 29, 2004, stated that the "starter was replaced with an overhauled unit and that the starter clutch was replaced with a serviceable unit," at an engine total time of 5,341.4 hours and 1,760.3 hours since major overhaul. After 7.7 hours of flight, the starter-clutch assembly was replaced again on August 27, 2004. At the time of the accident, the airplane had accumulated 7.94 hours of flight since the second replacement of the starter-clutch assembly. The Continental O-200-A engine was examined on November 3, 2004, by a representative from Teledyne Continental Motors, an FAA inspector, and the NTSB investigator-in-charge (IIC). The examination revealed the starter-clutch assembly would not rotate freely. The starter-clutch shaft was severed into two pieces, and the bolts that attach the accessory drive-gear to the camshaft were also severed. On November 4, 2004, a representative from Teledyne Continental Motors, under the supervision of the NTSB, examined the starter-clutch assembly at the facilities of Air Salvage of Dallas, near Lancaster, Texas. After disassembly of the clutch assembly, it was noted that the clutch rollers were shifted sideways, and two of the rollers were fused to the starter-clutch drive-shaft.