Ben Guerir
On 10 March 1956, four B-47s left MacDill Air Force Base in Florida for a non-stop flight to Ben Guerir Air Base in Morocco. After descending through clouds to begin their second round of aerial refueling over the Mediterranean Sea at 14,000 feet, one of the four aircraft, serial number 52-0534, failed to make contact with the tanker; neither the aircraft (which was carrying two nuclear weapon cores) nor its personnel were ever found.