The aircraft impacted level terrain at about 1140 Pacific, following the pilots declaration of an emergency. The Private pilot and one passenger sustained serious injuries; two other passengers sustained fatal injuries. The airplane was destroyed. Visual conditions prevailed. Although the airplanes destination was Prescott, Ariz., shortly after departing Santa Barbara, Calif., the pilot told ATC he wanted to divert to Oxnard, Calif., to check a few things out. After declining to declare an emergency, the pilot then told ATC he wanted to divert to Camarillo, Calif. When the pilot checked in with the CMA controller, he was unable to provide his current location. After using his transponders ident feature, ATC located the flight three miles north of the airport at 1000 feet, and the controller cleared the pilot for landing. The pilots last transmission was that he was not going to make the airport, and declared an unspecified emergency. The last radar return was within mile of an airport at Santa Paula, Calif. No obvious mechanical problems were discovered in the airplanes wreckage.