On December 19, 2012, about 1700 central standard time, a Piper L-18C airplane, N3134G, was substantially damaged during a forced landing near Graham, Texas. The private pilot and passenger were not injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from the Graham Municipal Airport (KRPH), Graham, Texas, about 1600. According to a statement provided by the pilot, when returning to the airport, he noted that the engine's oil pressure went to zero, the rpms began to reduce, and the engine power decreased. As the pilot maneuvered to perform a forced landing, the engine seized and the propeller stopped. The airplane landed hard, bounced, and nosed over, coming to rest in the inverted position. The airplane sustained substantial damage to the wings and rudder. An examination of the engine revealed a broken connecting rod and damage to the engine case. The reason for the failure of the connecting rod could not be determined.