The airplane sustained substantial damage at about 1445 Pacific time following loss of engine power and a subsequent forced landing. The solo private pilot received minor injuries. Visual conditions prevailed. Abeam the approach end of the runway, the pilot retarded the throttle to about 1000 rpm, then attempted to add power. There was no response from the engine. After a right turn onto base leg, the engine quit. The pilot then turned left 180 degrees and made a forced landing in an open field, during which the airplane nosed over after impacting a fence. The airplane had been topped off with fuel that morning; the accident flight was the airplanes first of the day.