A twin-engine seaplane lost one of its wings before it crashed off Miami Beach into the city's main shipping channel killing at least 19 people on board, a US federal safety official said on Tuesday. Mark Rosenker, acting chairman of the National Transportation Safety Board, told a news conference the breaking apart of the aircraft could be seen in video footage of the Grumman G-73T Turbine Mallard, filmed in its final moments on Monday above water. "What I've seen is a separation of a wing from the aircraft and, as a result, the aircraft crashing. I can't tell you why,"...