A 16-year-old Chinese student who initially survived the crash of Asiana Airlines Flight 214 at the San Francisco International Airport was killed when at least one fire truck rushing to the scene ran over her, the San Mateo County coroner confirmed Friday.

The cause of Ye Meng Yuan's death was "multiple blunt injuries that are consistent with being run over by a motor vehicle," Robert J. Foucrault said at a press conference in San Mateo, Calif., south of San Francisco

"She was alive at the time," the coroner said.

Ye Meng Yuan was one of three people, of a total 307 passengers and crew aboard the plane, who died as a result of the July 6 crash. Her classmate, 16-year-old Wang Linjia, died in the crash itself while 15-year-old Liu Yipeng died in hospital July 12 as a result of injuries sustained in the crash.

The middle-school students were part of a group of pupils and teachers from China travelling to a Christian summer camp in the San Fernando Valley.

Foucrault met with the families of the three deceased passengers on Thursday to relay the results of his investigation.

'Devastating news': fire chief

The San Francisco Police and the National Transportation Safety Board are both investigating what caused the Boeing 777 jet to crash while landing and how the rescue of passengers and crew from the burning wreckage of the plane unfolded.

San Francisco Fire Department Chief Joanne Hayes-White said Friday that the fire department is examining every aspect of its response to the crash.

"The coroner's finding [is] very difficult and devastating news for all of us," she said.

Hayes-White said Ye Meng Yuan was likely run over by one of the so-called ARFF (aircraft rescue and firefighting) vehicles that are part of the department's 95-member crew based at the airport. She said it is unclear whether more than one vehicle was involved in the accident.

"Many vehicles were in the area, near the aircraft," she said.

Chaotic scene

The scene at the airport after the crash was a "volatile, dangerous situation" that proved challenging for firefighters, Hayes-White said, with debris strewn everywhere, passengers still on the plane, fuel leaking from the wreckage and flames that had to be suppressed.

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The scene of the crash was chaotic, San Francisco Fire Department Chief Joanne Hayes-White told reporters Friday, and many vehicles were part of the rescue operation. (Eugene Anthony Rah/Handout/Reuters)

She stressed that despite the difficult circumstances, firefighters managed to rescue the majority of passengers from the blazing wreckage.

"We're in the business of saving lives," Hayes-White said. "Many lives were saved that day."

She said it was not yet clear what role fire-retardant foam played in obscuring Ye Meng Yuan, who was lying on the tarmac when she was run over.

It was reported earlier that foam that had been applied to suppress the fire on the aircraft might have covered up the girl and prevented the driver of the fire truck from seeing her.

Still unclear how girl got off plane

Foucrault told reporters on Friday that his investigation did not reveal whether the girl was thrown from the plane.

"We don't know how she got to where she was at," the coroner said.

Foucrault also said that Ye Meng Yuan's body was crushed to such an extent that it was hard to draw any conclusions about what injuries she may have sustained in the plane crash itself.

"It would be difficult to find out if there was another event before contact with the motor vehicle," he said.

But he stressed the internal hemorrhaging his investigation found left no doubt that she was alive before she was run over.

Hayes-White said her department has reached out to the Chinese consul general in San Francisco and offered to meet with the girl's family face to face.

"There's not a lot of words for how badly we feel about it, how sorry we feel about it," she said.

The fire chief said there is nothing to suggest that the driver of the vehicle involved should face disciplinary action.

"I consider it a tragic accident," Hayes-White said.

With files from the Associated Press