On August 1, 2010, about 0950 mountain daylight time, a Cessna 172P airplane, N52708, was substantially damaged during a forced landing near Santa Fe, New Mexico, which resulted from a total loss of engine power. The private pilot and passenger were not injured. The personal flight originated at Santa Fe Municipal Airport (SAF), Santa Fe, New Mexico, and was en-route to Double Eagle II Airport (AEG), Albuquerque, New Mexico. The airplane was operated by Sierra Aviation, LLC, and the flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident. The pilot reported he had just departed SAF and was at less than 500 feet above the ground when his attention was drawn outside to look for traffic in the area. When he looked back inside and performed a scan of the engine instruments he saw the oil pressure gauge was at zero. Shortly afterward the engine seized. The pilot then performed emergency forced landing on a nearby mesa. During the descent, smoke was present both inside and outside the cockpit, with the majority of the smoke outside. During landing, the airplane impacted a short rock wall. When the pilot and passenger exited the airplane smoke and flames were coming from the engine compartment. Most of the airplane was consumed during the ensuing fire. Maintenance had been performed on the airplane on June 4, 2010, to replace the oil cooler with an overhauled unit. According to the mechanic that worked on the airplane, an oil leak was discovered in the vicinity of the oil cooler and oil filler tube a couple of days before the accident. He said he removed the cowl, cleaned the cowl and engine thoroughly, and ran the engine for several minutes at various power settings. After shutdown, he was unable to identify any leak and surmised that the oil dipstick might not have been secured. After the next flight an oil leak was evident so he elected to replace the oil cooler, which occurred on July 31, 2010. He also replaced both safety wires on the oil filler tube. Following a short run up there were no leaks detected. He did state he didn’t think the engine was warm enough to close the oil cooler bypass. The airplane was subsequently dispatched on the accident flight the next morning. A Federal Aviation Administration inspector could not identify the source of the oil leak or fire during a postaccident examination due to the impact damage and fire to the airplane.