CAMARILLO, Calif. -

Authorities say debris at the site of a civilian training jet crash in Southern California covers an area about the size of a football field.

Authorities say the civilian pilot died in Friday's crash near Naval Base Ventura County. Fire Department spokesman Steve Swindle says the plane was a high-performance military-style aircraft on lease to the military from a private company.

Swindle says the Hawker Hunter jet trainer took off from the base on a training sortie with another aircraft and went down as it was returning, about two miles from the runway in the middle of a farm field.

The cause of the crash isn't yet known. Swindle said the sky was "bright and crystal clear."

The jet was owned by Airborne Tactical Advantage Co., which provides aerial training to the military.