Official Probes If Rescuers Ran Over Crash Victim Pilots of Asiana Flight 214 were flying too slowly as they approached San Francisco airport, triggering a control board warning that the jetliner could stall, and then tried to abort the landing seconds before crashing, according to federal safety officials. Investigators also said they were looking into the possibility that rescue crews ran over one of the two teenagers killed in the crash on Saturday. Officials released the details without explaining why the pilots were flying so slow - or why rescue officials didn't see the girl. The Boeing 777 was traveling at speeds well below the target landing speed of 137 knots per hour, or 157 mph, said National Transportation Safety Board chief Deborah Hersman at a briefing Sunday on the crash. "We're not talking about a few knots," she said. Hersman said the aircraft's stick shaker - a piece of safety equipment that warns pilots of an impending stall - went off moments before the crash. The normal response to a stall warning is to increase speed to recover control. There was an increase several seconds before the crash, she said, basing her comments on an evaluation of the cockpit voice and flight data recorders that contain hundreds of different types of information on what happened to the plane. And at 1.5 seconds before impact, there was a call for an aborted landing, she said. The new details helped shed light on the final moments of the airliner as the crew tried desperately to climb back into the sky, and confirmed what survivors and other witnesses said they saw: a slow-moving airliner. Pilots normally try to land at the target speed, in this case 137 knots, plus an additional five more knots, said Bob Coffman, an American Airlines captain who has flown 777s. He said the briefing raises an important question: "Why was the plane going so slow?" The plane's Pratt & Whitney engines were on idle, Hersman said. The normal procedure in the Boeing 777, a wide-body jet, would be to use the autopilot and the throttle to provide power to the engine all the way through to landing, Coffman said. There was no indication in the discussions between the pilots and the air traffic controllers that there were problems with the aircraft. Among the questions investigators are trying to answer was what, if any, role the deactivation of a ground-based landing guidance system played in the crash. Such systems help pilots land, especially at airports like San Francisco where fog can make landing challenging. Altogether, 305 of the 307 people aboard made it out alive in what survivors and rescuers described as nothing less than astonishing after a frightful scene of fire burning inside the fuselage, pieces of the aircraft scattered across the runway and people fleeing for their lives. The flight originated in Shanghai, China, stopped over in Seoul, South Korea, before making the nearly 11-hour trip to San Francisco. The South Korea-based airline said four South Korean pilots were on board, three of whom were described as "skilled." Among the travelers were citizens of China, South Korean, the United States, Canada, India, Japan, Vietnam and France. There were at least 70 Chinese students and teachers heading to summer camps, according to Chinese authorities. As the plane approached the runway under clear skies - a luxury at an airport and city known for intense fog - people in nearby communities could see the aircraft was flying low and swaying erratically from side to side.