A Boeing 777 jet has crashed while attempting to land at San Francisco airport, US aviation authorities confirmed on Saturday. <br /><br />The Federal Aviation Administration (FAA) confirmed that a plane, thought to be operated by Asiana Airlines and reported as Asiana 214, came down at the international airport. A Boeing 777 can carry up to 300 passengers. There was no immediate word on any casualties. <br /><br />Footage from the scene of the accident showed billowing smoke coming from the plane, which reportedly encountered problems as it prepared to touch down. <br /><br />Fire fighters are on the scene. It was reported that the plane was an inbound flight from Seoul, South Korea. <br /><br />A plane-spotter, Anthony Castorani, told CNN he heard a "pop" as the plane landed, followed by a brief fireball at which point the jet began to cartwheel. Castorani, who was watching aircraft land from a nearby hotel room, said there was no indication that the airport was prepared for an emergency landing. <br /><br />"It was coming in very nicely," he told CNN. But as it landed he witnessed a larger plume of smoke from the landing gear than is usually seen. After a "pop" he saw a brief fire take hold at which point the plane's tail became detached. <br /><br />"[The plane] lifted and began to cartwheel," Castorani added. <br /><br />Footage of the wreckage confirmed that the tail had come off. The main body of the plane showed extensive fire damage. <br /><br />A man who claims to have been on board the flight posted a picture of passengers leaving the plane via Twitter. <br />vedat şafak yamı
