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

USS San Diego Hits Mine-- Part 2: Off the U.S. Coast

The USS San Diego was recommissioned April 7 for use in World War I.  At first it operated in the Pacific before being ordered to the Atlantic.  Once there, the main job of the ship was to escort convoys across the North Atlantic to Europe.Ir was based out of Tompkinsville, New York, (Staten island) and Halifax, Nova Scotia.

An 18 July 1918, the San Diego was going to escort a convoy to France and its commander, Captain Harley H. Christy, ordered a zig-zag course with everyone on full alert for a submarine attack.  At 11:05 the next day, the ship was off Fire Island Lightship, N/Y/, when there was an explosion on the port side , well below the waterline.

Captain Christy thought his ship had been struck by a torpedo.  The San Diego began sinking rapidly and went below the water in 28 minutes.  Six men were killed.

--Cooter

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