UPDATE: San Francisco General Hospital and Trauma Center is treating eight adults and two children -- all of them in critical condition -- who were injured in Saturday's Asiana Airlines crash at San Francisco International Airport, the hospital said in a statement. Six of the patients are female and four are male.
A Boeing 777 bound from South Korea crashed Saturday upon landing at San Francisco International Airport, sending up a huge fireball and spinning before finally coming to a stop -- having lost its tail and, eventually, much of its charred roof.
Asiana Airlines Flight 214 left Seoul's Incheon International Airport earlier Saturday, according to FlightAware, a website that offers tracking services for private and commercial air traffic. An airline spokesman told CNN that 291 passengers and 16 staff members were aboard, an Asiana Airlines spokesperson told CNN from Seoul.
The U.S. Coast Guard has transported one person to Stanford Hospital, said Corrine Gaines of the military branch. She did not provide additional information on the patient's status. In brief remarks to reporters around 2 p.m. (5 p.m. ET), airport spokesman Doug Yakel did not offer any details on the conditions of the plane's passengers.
Air traffic control audio -- between the airport's tower and Flight 214 crew members -- suggested that those on the ground knew there was some sort of problem, promising that "emergency vehicles are responding."
"We have everyone on their way," the air traffic controller said, according to LiveATC.net, a website that provides air traffic control audio.
Anthony Castorani, who witnessed the flight land from a nearby hotel, said he saw the plane touch the ground then noticed a larger plume of white smoke.
"You heard a pop and you immediately saw a large, brief fireball that came from underneath the aircraft," he told CNN.
Kristina Stapchuck saw the dramatic scene unfold from her seat on a plane on the airport tarmac. Soon after Flight 214 touched down, "it looked like the tires slipped a little bit and it rocked back," she told CNN.
Parts of the plane began to break off as it rocked and then began to spin.
"It all happened so suddenly," Stapchuck told CNN.
A photo provided to CNN by Eunice Bird Rah -- and shot by her father, who was a passenger on the plane -- shows flames and smoke bursting out of many of the aircraft's windows.
Rah's father knew something bad was coming, he told his daughter, telling her the plane was coming in too low and the pilot tried to raise it at the last minute. Rah said her father "is doing fine, thank God," but noted that others appeared to be hurt.
Said Rah: "It's heartbreaking."
Video taken soon after the crash and posted on YouTube showed dark gray smoke rising from the plane, which appeared to be upright. That smoke later became white, even as fire crews continued to douse the plane.
CNN iReporter Timothy Clark was on an eighth-floor balcony of a nearby hotel when he heard the noise and saw a "dust cloud."
"Then people running from the plane, then flames," Clark said.
A photograph posted to Twitter shows what appear to be passengers walking off the plane, some of them toting bags, as smoke rises from the other side.
"I just crash landed at SFO," read the accompanying message from David Eun. "Tail ripped off. Most everyone seems fine. I'm ok. Surreal..."
The top of the aircraft was charred and, in spots, gone entirely, according to video from CNN affiliate KTVU. The plane was on its belly, with no landing gear evident and the rear tail of the plane gone.
Debris settled from the water's edge, along San Francisco Bay, up to where the plane eventually came to a stop.
Fire trucks were on site; first responders could be seen walking outside the aircraft.
Evacuation slides could be seen extending from one side of the aircraft, from which there was no apparent smoke.
Sheryl Sandberg, Facebook's chief operating officer and author of the book "Lean In," was supposed to be on the flight.
But she wrote on her Facebook page that she'd switched instead to a United flight, arriving about 20 minutes before the Asiana flight crashed.
The Bay Area airport was closed to incoming and departing traffic after the crash, the Federal Aviation Administration said on its website, adding that the time when it's expected to reopen is unknown.
Flights destined for San Francisco's airport -- known by its call letters, SFO -- were being diverted to airports in Oakland, Sacramento, San Jose and Los Angeles, said Francis Zamora from the San Francisco Department of Emergency Management. He added his office is working with San Mateo County's Office of Emergency Services in responding to the incident, Zamora said.
San Francisco International Airport, located some 12 miles south of downtown San Francisco, is California's second busiest, behind LAX.
There were a few clouds in the sky around the time of the crash, and temperatures were about 65 degrees, according to the National Weather Service. Winds were about 8 miles per hour.
The National Transportation Safety Board is sending a "go team" that will be led by chairwoman Deborah Hersman to investigate the crash, the agency said. Boeing is "preparing to provide technical assistance" to investigators, company spokesman Miles Kotay said in a statement.
There are no signs of terrorism related to the crash, a national security official told CNN. President Barack Obama was at Camp David when he learned about the crash, a senior White House official said.
Asiana Airlines -- one of South Korea's two major airlines, the other being Korean Air -- is investigating the cause of the crash, a company spokesman told CNN.
The airline got the plane involved in the incident in 2006, according to the Aviation Safety Network. The craft has two Pratt & Whitney engines, it said.
Asiana operates many of its flights out of Incheon International Airport, which is the largest airport in South Korea and considered among the busiest in the world.
According to information on Asiana Airlines' website, the company has 12 Boeing 777 planes. They have a seating capacity of between 246 and 300 people and had a cruising speed of 555 mph (894 kph).