Three people were killed early Sunday morning in northern Los Angeles when their helicopter, which was shooting footage for an upcoming military reality show for Discovery Channel, crashed in the remote Polsa Rosa Ranch near Soledad Canyon Road in Acton.

The crash is being called the worst on-set accident in California in over 30 years.

"A production company was shooting a show for Discovery Channel when this tragic accident occurred," Discovery said in a statement following the news that the crash killed three from the reality show. "We are all cooperating fully with authorities. Our thoughts and prayers go out to the families."

The name of the Discovery show the fallen helicopter was shooting footage for is "Untitled Military Project" according to a permit issued by FilmL.A., a non-profit group that processes permits for filming on-location on behalf of the City and County of Los Angeles.

"It's a grievous accident and our hearts go out to the people affected by it," said Phil Sokoloski, spokesman for FilmL.A.

The group says the Discovery film crew had a permit to film at the location from 5 p.m. Saturday to 7 a.m. Sunday.

The helicopter crash took place at 3:40 a.m., only a few hours before the end of the reality show shoot, Los Angeles County Fire dispatcher Robert Diaz told the AP. The names of the three people killed in the reality show crash were not immediately released.

The last time a film shoot saw this kind of carnage, was 25 miles away from the site of Sunday's helicopter crash, where actor Vic Morrow and two children were killed in a helicopter crash while filming the "Twilight Zone" movie in 1982.

That crash led to widespread changes regarding safety on film sets. At the time of the accident, director John Landis and four others were charged with involuntary manslaughter. All were later acquitted.