SAN FRANCISCO (CNN) -- Investigators looking into the fatal crash of Asiana Airlines Flight 214 are focusing on the crew and aircraft as they try to understand why the giant jet clipped the end of runway before crashing, the chairwoman of the National Transportation Safety Board said Monday.
"We're certainly looking at the crew and how they operated, how they were trained, at their experience," NTSB Chairwoman Deborah Hersman told CNN's "New Day."
"We're also looking at the aircraft. We're looking to see if the crew was using automation or was flying on autopilot, or they were hand-flying the airplane," she said.
Like many modern aircraft, the Boeing 777 is capable of landing automatically, but it was unclear if the plane's computer was handling Saturday's attempted landing or if it was being done by the pilot, who Asiana said was making his first San Francisco landing at the controls of that model of aircraft.
The flight, with 307 people on board, originated in Shanghai, China, and stopped in Seoul, South Korea. It was preparing to land Saturday in San Francisco when the rear of the plane struck the edge of the runway, severing the tail. Most passengers were able to escape before the plane erupted in smoke and flames.
Two people died, although the San Francisco Fire Department said one of those may have been run over by an emergency vehicle, San Mateo County Coroner Robert Foucrault said.
The victims, teenagers Ye Mengyuan and Wang Linjia, were among 35 Chinese students headed to California to attend West Valley Christian School's summer church camp, the school said on its website.
NTSB spokeswoman Kelly Nantel said the agency was aware of the reports that one of the girls may have died after being run over on the tarmac but did not have details.
The San Francisco Fire Department has not responded to CNN's request for comment.
Pilot's flight record
Lee Kang-kuk, the pilot who was in the captain's seat of Flight 214, had flown from Seoul to San Francisco several times between 1999 and 2004, the airline said.
But Saturday marked his first time landing a Boeing 777 at San Francisco International Airport and was the ninth time he had flown the model, with 43 hours at the controls, the airline said. He has about 10,000 hours as a pilot, Asiana said.
Hersman, who has discouraged speculation about whether the crew bore responsibility for the crash, downplayed the significance of the pilot's experience in her "New Day" interview.
"It's not unusual for crew to change aircraft types," she said. And with air crews flying all around the world, it's not unusual for pilots to fly into unfamiliar airports for the first time either.
She said it's important for the two pilots in charge of the aircraft during the "very risky" landing phase to work closely together, and while she said investigators have no evidence of cockpit communications problems, it's something investigators will be looking at, she said.
Mary Schiavo, a former inspector general for the U.S. Department of Transportation, said video and other data related to the crash suggest the crew "lost situational awareness" while approaching the airport at what Hersman said was significantly less than the necessary 137 knots (157 mph).
"They're low and slow and that's a problem," Schiavo said.
All four pilots have been interviewed by NTSB and South Korean investigators, said Choi Jeong-ho, the head of South Korean's Aviation Policy Bureau.
"We cannot reveal what's been said as it is an ongoing investigation," Choi said.
Hersman said that in most airplane crashes, investigators rarely find a single explanation for what went wrong.
"In most of our investigations, we find that it's not just one thing, it really is a combination of factors that lead to an accident," she said.
While weather has been ruled out as a factor, other factors officials are investigating include whether construction at the airport may have played a role, Hersman said Sunday.
Work to extend a runway safety area required the temporary shutdown of a system designed to help pilots land planes safely, she said.
Clues from voice recorder
The pilots apparently tried to speed up seven seconds before the crash, cockpit voice and flight data recorders showed.
A stall warning sounded three seconds later, telling the pilots the plane was about to lose its ability to stay in the air.
Then -- just 1.5 seconds before the plane slammed into the runway -- the crew decided to call off the landing and try to pull up for another try, Hersman said.
It was too late.
The frightening crash
With no warning from the cockpit, survivors said, the plane's rear struck the sea wall at the end of the runway. The impact severed the plane's tail and sent the rest of the body spinning on its belly.
Amateur video obtained exclusively by CNN shows the plane crashing and spinning counterclockwise and coming to a stop.
In addition to the two deaths, 182 people were hospitalized with injuries ranging from severe scrapes to paralysis.
"We're lucky there hasn't been a greater loss of life," San Francisco Fire Chief Joanne Hayes-White said.
A number of the injured passengers remained hospitalized Monday, including six in critical condition at San Francisco General Hospital, said Dr. Margaret Knudson, the hospital's chief of surgery.
About half of those admitted to the hospital had spinal fractures, she said. Others have head trauma.
"Their recovery could be months and months and maybe not even to full recovery," she said.
Many of the injured said they were sitting toward the rear of the aircraft, Knudson said.
But 123 of the 307 people on board walked away uninjured. Benjamin Levy was among them.
"Honestly, I was waiting for the plane to ... start flipping upside down, in which case I think a lot of people would have not made it," Levy said.
"If we flipped, none of us would be here to talk about it," he said.
CNN's Dan Simon, Dana Ford, Thom Patterson and Aaron Cooper contributed to this report.
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