At 15:40 Pacific time, a Cessna 210K lost engine power and made a forced landing near Oxnard. The pilot, his passenger and two dogs were not injured. The flight had been airborne for about 30 minutes when the pilot noted an abnormal vibration that increased despite his attempts to correct the problem. He declared an emergency and was given vectors to the nearest airport, but the engine quit entirely. He spotted an open area and made a forced landing off-airport, where the airplane hit trees and a fence. The original Continental IO-520 engine had been replaced 57 hours earlier by a Continental IO-550 under an STC.