Two people are dead and more than 180 injured after a Boeing 777 crashed and ignited into a fireball this afternoon as it touched down at San Francisco International Airport.

At least 10 of the survivors were believed to be in critical condition, including eight adults and two children, a San Francisco General Hospital spokeswoman told KCBS radio. The plane reportedly carried a group of vacationing South Korean school kids.

Officials said 181 people were taken to local hospitals One passenger is still unaccounted for.

MORE PHOTOS: SAN FRANCISCO JET CRASH

“I just crash landed at SFO. Tail ripped off. . . . Surreal,” tweeted passenger David Eun, an executive vice president of Samsung.

One witness told The Post the ill-fated Asiana Airlines Flight 214 from Seoul appeared to bounce off the ground and nearly flipped.

“I saw this plane coming in, at first it looked like a normal landing,” said Kate Belding, 56. “But then all of a sudden I noticed a puff of dust or dirt from right where the plane was landing. It was like it bounced, and it was a big loud bang, and then one of the wings went up and went back and [it] almost cartwheeled.”

The mother of two from Burlingame, Calif., was out for a run on a jogging path that lines San Francisco Bay, across from the airport.

The jetliner appeared to wobble before it came down, she said.

“There was a big, big, ‘boom-boom’ when it hit, two times, and it kind of bounced. It looked like it came down flat on its belly.”

A tremendous cloud of smoke obscured Belding’s view of the aftermath. She and a nearby runner shared the terrifying moment.

“We looked at each other and said: ‘Did you just see that?’ ” Belding said. “She was in tears and we were both just in shock.”

More than 300 people — 291 passengers and 12 crew members — were on the 10-hour flight when the fiery disaster unfolded on runway 28L about 2:38 p.m. Eastern time.

Passengers fled the crippled, smoking fuselage on inflatable emergency chutes.

“Omg a plane just crashed at [San Francisco Airport] on landing,” tweeted Google marketing exec Krista Seiden, who later added: “Smoke appears to be getting worse, lots of emergency personal at site … Plane came down and hit on its belly, immediately enveloped on [sic] smoke.”

One bystander said a wing “caught on the runway.”

“Literally just witnessed a plane crash start to finish,” tweeted Danielle Wells. “I cannot stop crying I can’t believe this. … came in straight but unstable and a wing caught under and just crashed.”

Nearly the entire roof of the doomed plane appeared ripped off or burned away, leaving a gaping, blackened hole across the top of the aircraft.

One engine appeared to have broken away and emergency responders could be seen walking inside the burned-out wreckage.

The National Transportation Safety Board deployed a team of investigators, led by Chairman Deborah Hersman, to determine the cause of the crash.

“It’s too early to tell,” Hersman said tonight from Washington, D.C.

There were no signs of terrorism, according to a published reports citing federal sources.

Footage of the crash posted to YouTube shows smoke pouring from the damaged plane, the roof of which appeared blackened and charred. Pieces of the aircraft, which skidded across the runway, were strewn across the tarmac.

The plane, which took off from Incheon Airport in South Korea’s capital, is believed to have landed, and then crashed, Federal Aviation Administration spokeswoman Laura Brown said.

The FAA canceled all flights in or out of San Francisco after the incident and roads surrounding the airport were closed.

Facebook CEO Sheryl Sandberg just missed being on the terror ride, choosing a flight on United Airlines at the last minute instead, according to NBC News.

“Serious moment to give thanks,” she wrote on Facebook.

The last fatal crash of a large commercial airliner in the U.S. was an American Airlines Airbus A300, Flight 587, in 2001. It took off from JFK Airport and plummeted into Belle Harbor, killing 265 people, including five on the ground.

Smaller airlines have had crashes since then. The last fatal U.S. crash was a Continental Express flight operated by Colgan Air, which crashed into a house near Buffalo on Feb. 12, 2009. The crash killed all 49 people on board and one man in a house.