At 10:10 Pacific time, a Piper PA-23 was damaged in a forced landing after a door opened in flight near Anza. The pilot suffered minor injuries. The pilot said he was at 9,500 feet msl when the cockpit door popped open. He said that he was unable to control the airplane in that configuration and subsequently initiated a reduced-power descent. He then performed an off-airfield, gear-up, forced landing in a flat, open, desert area.