Six people were killed when a small plane crashed in a field and burst into flames during the second of two landing attempts in fog just before dawn Saturday at a Southern California airport, 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 charred about an acre of vegetation at the edge of French Valley Airport, said the Riverside County Fire Department.

The jet, which can seat up to 13 people, crashed about 500 feet (150 meters) short of the intended runway, said Elliott Simpson, an investigator with the National Transportation Safety Board.

Read: How 4 children survived 40 days after plane crash in Colombia’s jungle

“Most of the airplane, with the exception of the tail, was consumed by fire,” Simpson told reporters at an afternoon briefing. Investigators were combing through a debris field about 200 feet (60 meters) long, he said.

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

The plane, which had departed from Harry Reid International Airport in Las Vegas for the 45-minute flight to Murietta, crashed during its second approach, the NTSB said. The pilot was cleared for a landing using only instruments because of limited visibility from the low cloud ceiling, Simpson said.

“The visibility and ceilings allowed for a landing, but it was right on the minimums" of the regulations set for that airport, he said. Investigators will review recordings between the pilot and air traffic control.

Read: Philippine plane crash kills 2, another carrying 6 missing

A preliminary report was expected in about two weeks, the NTSB said.

The FAA’s aircraft tracking database lists the jet as owned by Prestige Worldwide Flights LLC of Imperial, California. Officials with the company could not be reached for comment.

It was the second fatal crash this week at the small county-owned airport in Murrieta, a city with 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.

Read more: Plane crash kills 2, burns homes in California neighborhood