An Alaska Airlines jet believed to be carrying 65 passengers and five crew from Mexico to San Francisco has crashed into the Pacific after reporting mechanical difficulties.
Flight 261 from Puerto Vallarta was reported to have crashed 20 miles north-west of Los Angeles airport at about 3.45 p.m. yesterday local time (11.45 GMT), the Federal Aviation Administration said.
Pieces of wreckage could be seen in the water but there was no sign of survivors.
A Coast Guard helicopter, a navy plane and small boats were last night searching a large field of debris off Point Mugu as darkness began to descend. Spotlights illuminated the water.
"We are conducting [search] efforts. There have been some bodies recovered at this time, no survivors," said Lieut Kein Reed, of the Coast Guard.
He was unable to provide the number of bodies.
"At this time, there are several Coast Guard [vehicles] that are converging on the scene," he said, adding that private boats were also helping with the effort.
The jet's crew had reported mechanical difficulties and asked to land at Los Angeles, said Mr Ron Wilson, a spokesman for the San Francisco airport.
The flight was scheduled to continue to Seattle after San Francisco.
"Radar indicates it fell from 17,000 feet and then was lost from radar," he said.
An FAA spokesman, Mr Mitch Barker, said the plane was a Boeing 737. A Boeing spokesman, Mr Craig Martin, said the company was told by Alaska Airlines that the plane was an MD80.
Alaska Airlines has an excellent safety record and has built itself into a western power by flying north-south routes on the US west coast. Its headquarters are in Seattle.
The airline operates several flights from Puerto Vallarta, a resort on Mexico's Pacific coast, to San Jose, San Francisco, and other California cities.
The US National Transportation Safety Board said early today it was assembling a "go-team" to investigate the crash.
"The NTSB is assembling an investigative go-team as part of its investigation into the crash of an Alaska Airlines flight this evening off the coast of California," the NTSB said in a statement. "Information is very sketchy at this point."