LOS ANGELES (AP) - Authorities have identified three people killed Sunday in a pre-dawn helicopter crash while filming for a new reality TV show for the Discovery Channel.

The copter crashed at about 3:40 a.m. at the popular filming location of Polsa Rosa Ranch in the Southern California city of Acton.

Coroner's spokesman Ed Winter identified the victims Monday as 59-year-old David Gene Gibbs of Valencia, Calif.; 46-year-old Darren Arthur Rydstrom of Whittier, Calif., and 45-year-old Michael William Donatelli of Indiana, Pa.

Autopsies were pending.

The show was listed on a filming permit as an untitled military-theme TV program. The production company and the Discovery channel offered their condolences to the families of the victims.

A Federal Aviation Administration spokesman says the cause and other circumstances surrounding the crash were still unknown.

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