SAN FRANCISCO — Investigators trying to understand why Asiana Airlines Flight 214 crash landed focused Monday on decisions made in the cockpit of the giant jet, where an experienced pilot was learning his way around a new aircraft and fellow pilots were supposed to be monitoring his actions.
Authorities also reviewed the initial rescue efforts after fire officials acknowledged that one of their trucks may have run over one of the two Chinese teenagers killed in the crash at San Francisco International Airport. The students were the only two fatalities.
The teenagers were close friends and top students.
Wang Linjia showed talent in physics and calligraphy; Ye Mengyuan was a champion gymnast who excelled in literature.
National Transportation Safety Board chairman Deborah Hersman said investigators watched airport surveillance video to determine whether an emergency vehicle ran over one of students. But they have not reached any firm conclusions.
The students had been seated in the rear of the aircraft, where many of the most seriously injured passengers were seated, Hersman said.
The NTSB also said part of the jet's tail section was found in San Francisco Bay, and debris from the seawall was carried several hundred feet down the runway, indicating the plane hit the seawall on its approach.
Investigators have said Flight 214 was flying "significantly below" its target speed during approach when the crew tried to abort the landing just before the plane smashed onto the runway. Authorities do not know yet whether the pilot's inexperience with the Boeing 777 and landing it at San Francisco's airport played a role.
The airline acknowledged Monday in Seoul that the pilot at the controls had little experience flying that type of plane and was landing one for the first time at that airport.
Asiana spokeswoman Lee Hyomin said pilot Lee Gang-guk had logged nearly 10,000 hours operating other planes but had only 43 hours in the 777.
NTSB lead investigator Bill English said pilot interviews were going slowly because of the need for translation. The interviews began only after agents from the Korean Aviation and Rail Accident Investigation Board arrived from South Korea.
New details of the investigation have also raised questions about whether the pilots may have been so reliant on automated cockpit systems that they failed to notice the plane's airspeed had dropped dangerously low, aviation safety experts and other airline pilots said.
Information gleaned from the Boeing 777's flight-data recorders revealed a jet that appeared to be descending normally until the last half-minute before impact.
The autopilot was switched off at about 1,600 feet, according to an account of the last 82 seconds of flight provided by Hersman.
A key question raised by the NTSB's account is why two experienced pilots apparently didn't notice the airspeed problem.
Part of the answer may lie in whether the pilot, after switching off the autopilot, still had the plane's autothrottle engaged.
More than 180 people aboard the plane went to hospitals with injuries. Remarkably, 305 of 307 passengers and crew survived. Only a small number were critically injured.
Many survivors have a surprising pattern of spine injuries that a doctor says shows how violently they were shaken despite wearing seat belts.
So far, two people are unable to move their legs — doctors don't yet know if the damage is permanent — and several others have needed surgery to stabilize their spines, said Dr. Geoffrey Manley, neurosurgery chief at San Francisco General Hospital.
Among the worst injuries are crushed vertebrae that compress the spinal cord, and ligaments so stretched and torn that they can't hold neck and back joints in place, Manley said.
Even among those who suffered mild spine trauma, Manley said he is struck by a pattern that shows how their upper bodies were flung forward and then backward over their lap belts.
Three firefighters and two police officers without safety gear rushed onto the plane to help evacuate trapped passengers, including one who was trapped under a collapsed bulkhead.
They had gotten everyone off the craft except one elderly man, who was in his seat, moaning and unable to move.
"We were running out of time," San Francisco Fire Department Lt. Dave Monteverdi recalled Monday at a news conference. "The smoke was starting to get thicker and thicker. So we had no choice. We stood him up and amazingly, he started shuffling his feet. That was a good sign . . . We were able to get him out and he was pretty much the last person off the plane."