Los Angeles County Fire dispatcher Robert Diaz says the crash occurred about 3:40 a.m. Sunday at the Polsa Rosa Ranch in Acton. Diaz says everyone on board died.
KCAL-TV quotes an LA Film Commission official who says a production company had filed permits to shoot a TV reality show on the ranch. Filming began Saturday and included the use of a helicopter.
Television footage showed mangled wreckage in a rugged canyon area near Soledad Canyon Road.