On June 16, 1996, at 1600 eastern daylight time, a Cessna 177RG, N2186Q, collided with a fence a during landing roll after a forced landing 15 miles south of Lake Placid, FL. The personal flight was conducted under the provisions of Title 14 CFR Part 91, and an instrument flight plan was activated. Visual meteorological conditions prevailed at the time of the accident. The airplane sustained substantial damage, and the private pilot nor the passenger sustained any injuries. The flight departed Tamiami Airport Tamiami, Florida enroute to Tallahassee, Florida, at 1500 hours. According to the pilot, approximately ten minutes into the flight, he advised the Miami air traffic controller of an engine fire and requested vectors to the nearest airport. The pilot was cleared to Placid Lakes airport 12 miles north of his position. The pilot shut down the engine, and the fire went out. The pilot made a forced landing in a pasture short of the airport. On landing roll the airplane collided with two fences. The examination of the engine revealed that the number two cylinder separated from the assembly. The subsequent engine examination disclosed severe fretting on the crankcase parting surfaces at the number two bearing saddle and dowels. The surface fretting observed in this case is typical of conditions associated with a loss of torque on mating surfaces. According to the operator, the engine was overhauled 291 flight hours before this flight.