It had been an uneventful 10-plus hour flight from Seoul, South Korea, approaching San Francisco's airport on a clear summer day. Then, in a few horrifying seconds, that calm was shattered.
A fireball erupted after the Boeing 777 airliner hit the runway hard around 11:30 a.m., rocked back and forth, spun around, shearing off the plane's tail. Scores of passengers and crew climbed out -- some jumping, others sliding down evacuation chutes as flames and smoke billowed from the aircraft's windows.
Two people were found dead outside the plane, according to San Francisco fire Chief Joanne Hayes-White. "My understanding is that they were found on the runway," she said. The airline identified the dead girls as students Wang Linjia and Ye Mengyuan, both 16.
Somehow, 305 others survived.
Said San Francisco Mayor Ed Lee: "This could have been much worse."
That's an understandable sentiment for anyone who heard passenger and eyewitness accounts, or saw the distressing, distorted images showing what remained of Asiana Airlines Flight 214. Some photos painted an almost otherworldly scene -- like one posted online by David Eun of passengers walking from the burning plane. Some dragged their carry-on bags. One man held his hands steady to snap a picture.
"I just crash landed at SFO," Eun wrote. "Tail ripped off. Most everyone seems fine. I'm ok. Surreal..."
CNN iReporter Timothy Clark watched from an eighth-floor balcony of a nearby hotel. He recalled hearing a bang, seeing a "dust cloud," then seeing "people running from the plane, then flames."
Elliott Stone was one of them. He was "10 seconds away from being home" when the airplane dipped "kind of sharp," followed by another adjustment "and then just boom, the back end just hit and flies up in the air and everybody's head goes up to the ceiling."
The first announcement "was everybody calm," Stone said, but he and others unbuckled anyway. He told CNN he jumped out a door, before slides had deployed and before first responders had arrived. When they did, they saw some people climbing out of San Francisco Bay around the airport, Hayes-White said.
Video taken soon after the crash and posted on YouTube showed dark gray smoke rising from the plane, which was upright on its belly, with no landing gear evident.
Its roof was charred and, in spots, gone entirely. The back of the plane appeared to have been lopped off entirely.
Eunice Bird Rah provided CNN a photo shot by her father, showing flames and smoke bursting out of many of the aircraft's windows.
Some 182 passengers and crew were being treated at Bay Area hospitals, with everything from spinal fractures to bumps and bruises, San Francisco deputy fire chief Dale Carnes said.
Rah's father is one of the 123 people who escaped -- physically, at least -- uninjured, according to Carnes. He's "doing fine, thank God," his daughter said.
It's not lost on her how horrible the whole scene was and how much more horrible it could have been.
"It's heartbreaking," she said.
No explanation yet on why this happened
Investigators from Washington and Seoul are heading to northern California trying to answer a simple question.
How did this happen?
While the exact cause will take months to determine, the South Korean Transport Ministry said "the tail of the Asiana flight hit the runway and the aircraft veered to the left out of the runway."
Members of South Korea's Aviation and Railway Accident Investigation Board will travel to San Francisco, that agency said. They'll be joined by a "go-to" team from the United States' National Transportation Safety Board, led by chairman Deborah Hersman. Right now, they're not sure what they'll find, though a U.S. national security official has said there are no signs of terrorism.
"We have not determined what the focus of this investigation is yet," Hersman said. "Everything is on the table at this point."
Watching from a nearby hotel, Anthony Castorani saw the plane touch the ground, then noticed a large plume of smoke.
"You heard a pop and you immediately saw a large, brief fireball that came from underneath the aircraft," he told CNN.