The airplane was substantially damaged during a forced landing at about 1035 Pacific time. The pilot received serious injuries; his three passengers received minor injuries. Visual conditions prevailed at the accident location. The airplane had departed on an IFR flight plan, which subsequently was cancelled while en route.
Shortly after the pilot began a slow descent for the destination, the airplane experienced a high-frequency vibration. The pilot reduced power and notified ATC of an engine problem. Engine power could not be restored. The pilot banked to the right to land in a field, but the right wingtip contacted a lake. The airplane “flipped” and came to rest inverted in water about one to three feet deep, approximately 1.25 miles southwest of the intended runway.