lands at San Francisco airport 6 July 2013 Last updated at 21:18 Katy Watson describes the scene as aerial views show the extent of the damage A Boeing 777 aircraft has crash-landed at San Francisco international airport. There is no word so far on casualties. The aircraft operated by the South Korean airline Asiana had taken off from Seoul and was on the runway, with plumes of smoke rising from it. Pictures posted on Twitter showed passengers jumping down the inflatable emergency slides and leaving the area. Firefighters and rescue teams are at the scene. The cause of the emergency is not known. There were reportedly 12 crew and 290 passengers on board - the Boeing 777 can carry as many as 300 passengers. While the sequence of events remains unclear, it appeared the plane landed and then crashed on San Francisco International Airport's Runway 28, said Federal Aviation Administration spokeswoman Laura Brown. Footage of the scene showed debris strewn on the runway and smoke pouring from the long-range jet. Passenger David Eun tweeted a picture of people jumping out of the plane 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. A witness to the crash, Anthony Castorani, told CNN that when the aircraft touched down on the runway there was a large fireball and the plane spun around before part of it broke off. Asiana is South Korea's second-largest airline.