Update-2 for Asiana Airlines Crash

The flight data recorder also showed that the Boeing 777 received a warning that its engines were likely to stall as it approached the runway, where it later burst into flames.

The request to abort the landing was captured on the cockpit voice recorder 1.5 seconds before the plane crashed, said National Transportation Safety Board chairwoman Deborah Hersman, who is leading the probe.

Ms Hersman's announcement came after a video obtained by CNN confirmed that the aircraft, carrying more than 300 people, clipped a seawall short of the airport and skidded on its belly on to the runway.

The footage showed the nose up with the rear of the plane hitting the ground first, before it rolled on to the concrete, abruptly bounced upward and then spun round 180 degrees.

The two passengers who died were teenage Chinese girls. A coroner says officials are conducting an autopsy to determine if one of the girls was run over and killed by a rescue vehicle, after firefighters said one of the 16-year-olds may have been struck on the runway.

Asked about the speed at which the plane was traveling, Ms Hersman, whose NTSB team is examining the wreckage, stressed that it was well below a desired pace of 137 knots.

“We have to take another look at the raw data and corroborate it with radar and air traffic information to make sure we have a very precise speed.

“But again, we are not talking about a few knots here or there. We're talking about a significant amount of speed below 137,” she said.

The crash sheared off the plane's landing gear and ripped the tail off. Large portions of the fuselage were burned out in the massive fire that erupted.

Ms Hersman refused to comment on whether the flight crew was at fault, noting that the pilots would be interviewed and stressing that it was day one of the investigation.

However she said the plane's low speed triggered an automatic device called a “stick shaker” which warns pilots that a plane is about to stall. The warning came four seconds before the crash - 2.5 seconds before one of the pilots tried to abort the landing.

Ms Hersman said: “There was a call out for a go around from one of the crew at 1.5 seconds prior to impact. And the call out is a - is communication between the crew that they want to go around, that means they want to not land but apply power and go around and try to land again.”

Analysts said the pilot's request came far too late.

Asiana Flight 214 originated in Shanghai, and had 307 people on board -- 291 passengers and 16 crew -- after it stopped to pick up passengers in Seoul.

Mr Yoon said the plane was being flown by experienced pilots, and there was no emergency warning ahead of the crash, adding “our pilots strictly comply with aviation rules.”

“Please accept my deepest apology,” the CEO added, bowing in front of TV cameras at a press conference in Seoul.

Several of the injured were still in critical condition or unconscious, said the San Francisco General Hospital.

Doctors saw “large amounts of abdominal injuries, a huge amount of spine fracture, some of which include paralysis, and head trauma and multiple type of orthopedic injuries,” Margaret Knudson, interim surgery chief at the hospital, told reporters.

Some 15 or 16 had yet to regain consciousness, she said, adding that “some of our patients have been operated on twice already, and there's going to be many many more surgeries to come still.”

Other patients had been sent to different area hospitals.

Aboard the flight were 141 Chinese nationals, 77 South Koreans, 64 Americans, one Japanese, three Indians, three Canadians, one French, one Vietnamese and three others of unidentified nationality. There were also 16 crew members, according to Asiana.

In total, 123 people aboard the flight escaped unharmed, US officials said.

San Francisco International Airport was closed after the crash but operating normally today.

The twin-engine 777 aircraft is one of the world's most popular long-distance planes, often used for flights of 12 hours or more, from one continent to another.

It was the first fatal crash involving an Asiana passenger plane since June 1993, when a Boeing 737 operated by the carrier crashed into a mountain in South Korea, killing 68.

AFP/AP