One passenger, Elliott Stone, told CNN he thought the Boeing 777, carrying 307 passengers and crew, approached the airport "a little high [then came] down a little sharp" as it approached San Francisco International Airport shortly before 11:30 a.m. PDT.
"All of a sudden, boom, the back end just hit and flies up into the air and everyone's head goes up the ceiling," said Stone, who added he leaped from the plane rather than use the stairs or an evacuation slide.
Confusion over the fate of those on board Flight 214 ended about 7:45 p.m PDT when San Francisco Mayor Ed Lee said everyone on board had been accounted for. Earlier, the city's fire chief had said more than 60 were unaccounted for, a number that was later reduced to one.
Deputy Fire Chief Dale Carnes said 49 of the 182 people taken to hospitals had serious injuries, while 123 uninjured people were at airport terminals.
National Transportation Safety Board investigators were sent to the scene to determine what went wrong, the Chronicle said.
"It's still too early for us to tell," safety board Chairwoman Deborah Hersman told reporters in Washington, D.C., when asked what she might have caused the crash. "We'll certainly be looking at everything once we get there."
The Federal Aviation Administration, the FBI, Boeing and the South Korean airline's personnel also were to take part in the investigation.
David Johnson, the FBI's special agent in charge for San Francisco, said, "There is no indication of terrorism involved" in the crash of the Boeing 777, which had 191 passengers and 16 crew members aboard.
The injured were taken to hospitals in San Francisco, San Mateo and Santa Clara, WPIX-TV, San Francisco, said.
Rachel Kagan of San Francisco General Hospital and Trauma Center said that hospital had received 34 patients, of which 23 were adults and 11 were children. She said five were in critical condition, down from 10 earlier.
KPIX-TV, San Francisco, reported two passengers relayed to a San Carlos relative by cellphone that the aircraft appeared to come down short of the runway.
Witnesses said there was a loud noise and they saw the tail come off the plane, which then erupted in flames.
"The plane started coming in at an odd angle, there was a huge bang and you could see the cloud of huge black smoke," Kate Belding, who was jogging nearby when she saw the crash.
Kelly Thompson, who was in a nearby parking lot when the plane came down, said it made "a horrible thud."
"The airliner bounced and then slid to a stop on the runway," Thompson said.
Ground crews quickly extinguished the flames. Passengers were seen using the aircraft's escape chutes.
Asiana Airlines said in a post on Twitter: "Our thoughts and prayers are with all the passengers and flight crew on the flight," the Chronicle said
Gov. Jerry Brown Jr. and his wife expressed their "deepest concerns and sympathy" to the passengers and their families.
"We are grateful for the courage and swift response of the first responders whose actions surely prevented an even greater tragedy," Brown said in a statement.
Lee said his thoughts and prayers were with the victims and their families.
"We are deeply saddened by this incident," he said.
The White House press secretary's office issued a statement, saying President Obama "was made aware of the incident by Lisa Monaco, assistant to the president for homeland security and counter-terrorism."
"The president will continue to be updated as new information becomes available," the statement said. "The president expressed his gratitude for the first responders and directed his team to stay in constant contact with the federal, state and local partners as they investigate and respond to this event.
"His thoughts and prayers go out to the families who lost a loved one and all those affected by the crash."
The airport was shut down for a time with two runways later reopened.
CNN said air traffic communications between the airport's tower and Flight 214 crew members indicated those on the ground knew a problem had arisen and assured "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.