All six people aboard a small jet died when the aircraft crashed and burned in a field near an airport near Los Angeles on Saturday.
The Cessna C550 business jet was travelling from Las Vegas and crashed near French Valley Airport in Riverside County, about 137 kilometres south of Los Angeles, at around 4.15am, the Federal Aviation Administration said.
The passengers and pilot who died were all adults, Elliott Simpson, an aviation investigator for the National Transportation Safety Board, said at a news briefing.
The privately owned plane crashed about 150 metres from the runway at the small airport, after attempting an instrument landing as a marine layer weather phenomenon settled on the area, Mr Simpson said.
The conditions appeared to have met minimum standards for a landing at the airport, he said.
The names of those killed have not been released.
Just days earlier, on July 4, a small aircraft with four occupants crashed near the same airport, killing the adult pilot and injuring three juveniles, authorities said.
In Saturday's incident, fire engulfed all but the tail of the aircraft after it crashed, Mr Simpson said.
Aerial videos from local media showed burnt debris in the shape of a small aircraft in a blackened part of a field across the road from the airport.
Radar data from the flight tracking website FlightAware showed one business jet travelling from Las Vegas to French Valley at the time. That plane circled once near the field before descending.
The sheriff's office in Riverside County, where the French Valley Airport is located, said officials located an aircraft engulfed in flames in a field and that six occupants were pronounced deceased at the scene.
The National Transportation Safety Board will continue to investigate the crash, with more results expected within the next two weeks, Mr Simpson said.
