Prime Minister Justin Trudeau and defense officials on Thursday said a Canadian sailor was killed and five were missing after a navy helicopter crash in the sea between Greece and Italy. The Cyclone Sikorsky CH-148 helicopter was returning to HMCS Fredericton when contact was lost, the chief of the defense staff, General Jon Vance, said. Defense Minister Harjit Sajjan added the cause of the crash was "unknown," but that the cockpit voice and flight data recorders had been recovered. amc/jm