MURRIETA, Calif. (AP) — Six people were killed when a small plane crashed and burst into flames in a field near a Southern California airport before dawn Saturday, authorities said.

The crash of the Cessna C550 business jet occurred around 4:15 a.m. in Murrieta, about 80 miles (130 kilometers) southeast of Los Angeles, according to the Federal Aviation Administration.

It took firefighters more than an hour to extinguish the flames, which had engulfed the plane and charred about an acre of vegetation just north of French Valley Airport, said the Riverside County Fire Department.

All six people on board died at the scene, the Riverside County Sheriff's Office said in a statement. The victims were not immediately identified.

The plane had departed from Harry Reid International Airport in Las Vegas, the FAA said.

The FAA and the National Transportation Safety Board will investigate.

It was the second fatal crash this week at the small county-owned airport in Murrieta, home to about 112,000 residents. A man was killed and three people were injured on July Fourth when a single-engine Cessna 172 crashed in a parking lot shortly after takeoff from French Valley.