According to a witness, around 11:30 a.m. the plane was just about to land -- its landing gear had come down -- when the tail of the plane came off. After wobbling for a minute, the aircraft flipped upside down, coming to a stop on runway on it's back, according to witness Kathy Muhler. When it came to a halt, smoke was pouring from the aircraft. Fire crews responded minutes later, Muhler said. According to Redwood City Fire Department, three alarms have been called and responding crews are reporting passengers in need of burn treatment. The plane, reportedly a Boeing 777, was identified as Asiana 214 and was coming from South Korea, according to flight tracking information. I'm surprised that a 777 crashed....