On March 13, 1996, at 0857 hours Pacific standard time, a Cessna T210M, N8683M, operated by the Diamond Well Drilling Company, Auburn, California, experienced a total loss of engine power while cruising en route to the Nevada County Air Park, Grass Valley, California. The commercial pilot made a forced landing and collided with the top of a commercial building and trees. The airplane came to rest in a ditch, about 200 feet from the approach end of Nevada County Air Park's runway 07. The aircraft was destroyed and the pilot sustained serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed. At the time of the accident, the pilot was ferrying the airplane to the operator's maintenance base for an engine inspection. The flight originated at Auburn about 0845. In the pilot's completed accident report, he indicated that he had performed a preflight inspection of the airplane before taking off. The pilot determined that at least 1 hour of fuel was onboard. The pilot reported to the Nevada County Sheriff's Department that during the flight, when he was about 7 miles south of Grass Valley and without any warning, he experienced an immediate power loss. Thereafter, engine power was not restored. Recovery personnel reported observing that a fuel line had ruptured forward of the firewall in an impact damaged area around the engine. Also, fuel was observed leaking onto the ground from an undetermined location in the empennage. No fuel was observed leaking out of the main wing fuel tanks. A Federal Aviation Administration (FAA) airworthiness inspector examined the airplane in conjunction with manufacturer participants from the Cessna Aircraft Company and Continental Motors. The FAA inspector reported that a complete fuel system inspection and analysis was performed. No evidence of preimpact discrepancies was found. A temporary fuel supply was attached to the airplane. The engine was started and operated with normal pressures.