A passenger video captures the panic aboard a Boeing 737 that filled with smoke. The drama happened shortly after Southwest Airlines flight 3923 left Havana for Fort Lauderdale, Florida, on Sunday, apparently losing an engine to a bird strike. As the cabin filled with smoke, passengers struggled to fit oxygen masks. Some passengers can be heard screaming while a male crew member appeals for calm. The aircraft quickly turned back for an emergency landing in the Cuban capital, passengers disembarking on slides. No injuries were reported.