CBS News: SAN FRANCISCO A federal aviation official says an Asiana Airlines flight has crashed while landing at San Francisco airport. It was not immediately known whether there were any injuries. Federal Aviation Administration spokeswoman Lynn Lunsford says the Boeing 777 crashed at San Francisco Airport while landing on Saturday. Asiana Flight 214 was arriving from Seoul. Photos and video of the aircraft show fire and smoke from the aircraft. Early reports indicate the tail came apart from the plane and the resulting fire sent black smoke billowing into the air, visible for miles. CBS Station KPIX reports witnesses heard a loud bang, and saw a huge cloud of smoke. Rescue vehicles were on the scene immediately afterwards. The airport has been closed — no flights were being allowed in or out of SFO at this time.