SAN FRANCISCO - Asiana Airlines Flight 214 was traveling well below its target speed for landing when it crashed short of the runway Saturday, National Transportation Safety Board Chairman Deborah Hersman said at a briefing Sunday.
"The speed was significantly below 137 knots, and we're not talking a few knots," she said.
They were headed to a three-week stay in Los Angeles at a church school in the San Fernando Valley, West Valley Christian School administrator Derek Swales said.
At least 168 people were treated for injuries. Eight were still in critical condition.
After the crash, smoke billowed from the jet, and frightened passengers scampered to safety from emergency exits on the plane's fuselage. A massive, gaping hole blackened by fire stretched along much of the plane's top.
It was the first fatal crash of a commercial airline in the USA since February 2009.
The flight, which originated in Shanghai before stopping in Seoul en route to San Francisco, carried 61 U.S. citizens, 77 South Koreans and 141 Chinese.
Early Sunday, South Korea's Ministry of Land, Infrastructure and Transport identified the two pilots flying the jetliner at the time of the crash as Lee Jeong Min and Lee Gang Guk. The ministry said four pilots were on board and rotated in two-person shifts during the 10-hour flight from Seoul.
Hersman said a component of the airport's instrument landing system that tracks the glide path of incoming airplanes was not working at the time of the crash, but other technology aids were available to the pilots on the final approach.
The computerized system calculates a plane's path of descent and sends the information to pilots in real time.
Vedpal Singh, who was sitting in the middle of the aircraft and survived the crash with his family, said there was no warning from the pilot or any crewmembers before the plane touched down hard and he heard a loud sound.
"We knew something was horrible wrong," said Singh, who suffered a fractured collarbone and had his arm in a sling. "It's miraculous we survived."
Passenger Benjamin Levy, 39, said it looked to him as though the plane was flying too low and too close to the bay as it approached the runway. Levy, who was sitting in an emergency exit row, said he felt the pilot try to lift the jet up before it crashed and thinks the maneuver might have saved some lives.
"Everybody was screaming. I was trying to usher them out," he recalled of the first seconds after the landing. "I said, 'Stay calm, stop screaming, help each other out, don't push.' "
After the initial impact, the plane's tail section was ripped off, coming to rest hundreds of feet from the main body of the aircraft, which burst into flames.
Samsung executive David Eun, who was aboard the aircraft, was among the first to tweet photos and word of passengers. "Fire and rescue people all over the place. They're evacuating the injured. Haven't felt this way since 9/11.''
William M. Welch reported from Los Angeles and Swartz from San Francisco International Airport; Contributing: Calum MacLeod, in Beijing, Gary Strauss, Donna Leinwand Leger, Bart Jansen, Ben Mautzabaugh, Elizabeth Weise, Nancy Trejos and Nancy Blair, USA TODAY; Associated Press