USS San Diego-- Part 3: Still the Question: Mine or Torpedo

The USS San Diego was the only major warship lost by the United States in World War I.

The Navy Department was informed that a German submarine was operating off the  east coast of the U.S. and the U.S. Naval Air Service was put on alert.  Aircraft of the 1st Yale Unit, based at Bay Shore, Long Island, attacked what they thought was a submerged submarine, but it turned out to be the San Diego.

Captain Christy believed his ship had been sunk by a torpedo, but there was no evidence of a submarine operating in the area at the time, not did his lookouts see the wake of a torpedo.  It had been reported that dive or six mines had been found in the area.

But the thought was that had it been a mine, the explosion would have taken place at the San Diego's bow or forward part of the ship.  Experienced merchant ship captains believed a mine was probable because of the force of the explosion and how rapidly the ship sank.

--Cooter