A Boeing 777 aircraft crash-landed at San Francisco

A Boeing 777 aircraft has crash-landed at San Francisco international airport, killing at least two people and injuring dozens more, officials say.

Pictures posted on Twitter showed passengers jumping down the inflatable emergency slides and leaving the area, as plumes of smoke rise from the plane.

Fire fighters and rescue teams are at the scene of the downed Asiana Airlines Flight 214, which had taken off from South Korea's capital, Seoul. The cause of the crash is unclear.

Early indications suggest the plane came in too short and hit the seawall at the airport. Eight adults and two children who suffered critical injuries are being treated at San Francisco General Hospital, hospital spokesperson Rachael Kagan said.

There were 291 passengers and 16 crew on board, Asiana said. Nationalities on board included 141 Chinese, 77 South Koreans and 61 US citizens, the airline said.

Rescue teams initially took 49 people deemed to be in a serious condition to nearby hospitals, officials said. Some 190 people walked to safety from the plane, many of whom were later treated for minor injuries.

Most of the remaining passengers were waiting in the airport terminals uninjured. One person remained unaccounted for.

While the sequence of events remains unclear, it appeared the plane landed and then crashed on San Francisco International Airport's Runway 28L, said Federal Aviation Administration spokeswoman Laura Brown.

Footage of the scene showed debris strewn on the runway and smoke pouring from the jet, as fire crews sprayed a white fire retardant into gaping holes in the craft's roof.

One engine and the tail fin appeared to have broken away from the main wreckage.

Passenger David Eun tweeted a picture of people jumping out of the plane's emergency inflatable slides and wrote: "I just crash landed at SFO. Tail ripped off. Most everyone seems fine. I'm ok. Surreal..."

Mr Eun, who describes himself as a "digital media guy" and "frequent flier", added: "Fire and rescue people all over the place. They're evacuating the injured. Haven't felt this way since 9/11."

Key words

首尔航空shǒu’ěr hánɡkōnɡ：Seoul Airlines
坠毁zhuì huǐ：(plane) crash
黑匣子hēi xiázi：(airplane) black box