At one point, the pilot of a United Airlines plane radioed.
"We see people ... that need immediate attention," the pilot said. "They are alive and walking around."
"Think you said people are just walking outside the airplane right now?" the controller replied.
"Yes," answered the pilot of United Flight 885. "Some people, it looks like, are struggling."
When the plane hit the ground, oxygen masks dropped down, said Xu Da, a product manager at an Internet company in Hangzhou, China, who was sitting with his wife and teenage son near the back of the plane.
When he stood up, he said he could see sparking -- perhaps from exposed electrical wires.
He turned and could see the tail where the galley was torn away, leaving a gaping hole through which they could see the runway. Once on the tarmac, they watched the plane catch fire, and firefighters hose it down.
"I just feel lucky," said Xu, whose family suffered some cuts and have neck and back pain.
In the chaotic moments after the landing, when baggage was tumbling from the overhead bins onto passengers and people all around her were screaming, Wen Zhang grabbed her 4-year-old son, who hit the seat in front of him and broke his leg.
Spotting a hole at the back of the jumbo jet where the bathroom had been, she carried her boy to safety.
"I had no time to be scared," she said.
At the wreckage, police officers were throwing utility knives up to crew members inside the burning wreckage so they could cut away passengers' seat belts. Passengers jumped down emergency slides, escaping from billowing smoke that rose high above the bay.
Nearby, people who escaped were dousing themselves with water from the bay, possibly to cool burn injuries, authorities said.
By the time the flames were out, much of the top of the fuselage had burned away. Inside The tail section was gone, with pieces of it scattered across the beginning of the runway. One engine was gone, and the other was no longer on the wing.
San Mateo County Coroner Robert Foucrault said senior San Francisco Fire Department officials notified him and his staff at the crash site on Saturday that one of the 16-year-olds may have been struck on the runaway.
Foucrault said an autopsy he expects to be completed by Monday will involve determining whether the girl's death was caused by injuries suffered in the crash or "a secondary incident."
He said he did not get a close enough look at the victims on Saturday to know whether they had external injuries.
Foucrault said one of the bodies was found on the tarmac near where the plane's tail broke off when it slammed into the runway. The other was found on the left side of the plane about 30 feet away from where the jetliner came to rest after it skidded down the runway.