On May 18, 2002, about 1430 Alaska daylight time, a float-equipped Cessna 180 airplane, N9024M, sustained substantial damage after colliding with trees during a forced landing, about 13 miles east of Skwentna, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight when the accident occurred. The airplane was operated by the pilot. The airline transport certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. The flight originated at the Lake Hood Seaplane base, Anchorage, Alaska, about 1355. The Federal Aviation Administration (FAA) Regional Operations Center notified the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on May 18, that the accident airplane had crashed, and an emergency locator transmitter (ELT) was being received from the accident site. The pilot and passenger were rescued by helicopter. During a telephone conversation with the NTSB IIC, on May 28, the pilot reported that the airplane was in cruise flight. He initiated a cruise climb, and heard a "snap" sound from the engine. The engine began to shake and vibrate, and was producing metal-to-metal sounds as it lost power. The pilot selected an emergency landing area on a small lake. The airplane touched down on the lake, but then collided with the shoreline and trees during the landing. The pilot said the lake was too small to successfully stop the airplane. The airplane received damage to the float assembly, and both wings. In the Pilot/Operator Aircraft Accident Report (NTSB form 6120.1) submitted by the pilot, the pilot indicated that the engine accrued 1,204.6 hours since the last overhaul. The pilot said he sold the airplane, "as is, where is," to a salvage company in Big Lake, Alaska. On October 24, 2002, personnel from the salvage company reported that their examination of the engine revealed the number five cylinder piston had disentegrated. The piston connecting rod, wrist pin, and the engine crankshaft were intact.