On September 30, 2000, at 0938 central daylight time (cdt), a Cessna 150H, N50318, operated by a private pilot, sustained substantial damage when it nosed over during a forced landing on a field, located 1/4 mile north of Michigan City, Indiana. Prior to attempting the forced landing, the airplane's engine lost power. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. No flight plan was on file. The pilot and passenger on board the airplane reported no injuries. The local flight originated at the Micigan City Municipal Airport, Michigan City, Indiana, at 0815 cdt. In his written statement, the pilot said he was flying over Lake Michigan, when the airplane's engine began to lose power. The pilot said he proceeded direct to the Michigan City Airport. While heading toward the airport, the pilot said he turned on the carburetor heat. He said that it had a "minimal effect, if any," on the engine's performance. The pilot said that he was about 1/4 mile from the end of the runway and realized that he was not going to make it. He located a baseball park and executed a forced landing to it. The pilot said he tried to stop as soon as he could, but there was a marsh/lake at the end of the field. He said that the nose gear broke in the mud and the airplane turned over. The pilot said that when the engine first began to run rough, he noticed that there was "approximately 1/4 tanks on board [the] aircraft." A Federal Aviation Administration inspector examined the airplane at the accident site. The airplane rested inverted on the edge of a small pond. The airplane's nose wheel was pushed up into the fuselage frame. The engine mounts were bent upward and aft. The firewall was wrinkled. The propeller was broken aft. The vertical stabilizer and rudder were crushed downward and bent over. Approximately 10 gallons of fuel was observed in the airplane's fuel tanks. Flight control continuity was confirmed. An examination of the airplane's engine showed water in the gascolator bowl. All of the engine spark plugs showed heavy carbon on their respective electrodes.