SAN FRANCISCO — Stunned and bleeding after a Boeing 777 crash-landed at the San Francisco airport, hundreds of passengers staggered across the debris-strewn tarmac, some trying to help the critically injured, others desperately calling 911.

“There’s not enough medics out here,” a caller told a dispatcher in a 911 call released by the California Highway Patrol.

Two people died and 180 of the 307 passengers were hurt Saturday when Asiana Airlines Flight 214 slammed into a seawall at the end of the runway. Authorities said Thursday that the landing gear hit first, followed by the tail.

The battered passengers, some with broken bones, were told over the jet’s public-address system to stay in their seats while the cockpit consulted with the control tower, a safety procedure to prevent people from evacuating into life-threatening fires or machinery.

“We don’t know what the pilots were thinking, but I can tell you that in previous accidents there have been crews that don’t evacuate. They wait for other vehicles to come, to be able to get passengers out safely,” said National Transportation Safety Board Chairman Deborah Hersman.

And in this accident, it appears one of the two Chinese teens who died may have been run over by a fire truck rushing to the burning jet.

Many passengers jumped out the back of the plane or slid down inflated slides.

911 tapes recorded frantic callers, pleading for help.

“We’ve been on the ground, I don’t know, 20 minutes, a half hour,” said one woman. “There are people laying on the tarmac with critical injuries, head injuries. We’re almost losing a woman here. We’re trying to keep her alive.”

San Francisco Fire Department spokeswoman Mindy Talmadge said Thursday that some passengers who called 911 may not have immediately seen ambulances because they were dispatched to a nearby area as first responders assessed who needed to be taken to the hospital.

Within 18 minutes of receiving word of the crash, five ambulances and more than a dozen other rescue vehicles were at the scene or en route, in addition to other agencies already on the scene, Talmadge said.

Most of the passengers who were hurt had minor injuries and were treated and released from hospitals. On Thursday, nine remained hospitalized, three in critical condition.

Among those who walked away without serious injury were the four pilots, including Lee Gang-kuk, who was landing the jet for the first time at the San Francisco airport, and Lee Jeong-Min, who was training him.

The trainee told investigators he was blinded by a flash of light at about 500 feet, which would have been the point at which the airliner began to slow and drop.

On Thursday, Hersman sought to clarify the pilot’s description, saying the light did not prevent him from seeing his instruments.

Details emerging from pilot interviews show the captains thought the airliner’s speed was being controlled by an autothrottle set for 157 mph.

Inspectors found that the autothrottle had been made ready for activation, Hersman said. Investigators are still determining whether it had been engaged. Even if the autothrottle malfunctioned, Hersman stressed, the pilots were responsible for control of the airliner.

“There are two pilots in the cockpit for a reason,” she said. “They’re there to fly, to navigate, to communicate and if they’re using automation, a big key is to monitor.”