The World War I U.S. Navy cruiser San Diego was sunk as a result of enemy action off the coast of New York on July 19, 1918, the US Navy announced after a two-year study into what sank the cruiser.
In July 1918, the 15,000-ton armored cruiser San Diego sank off Long Island, New York, after being hit by an explosion.
Until now, no one was actually sure what caused the explosion. German submarines had mined the coast, implicating a mine. But the ship’s captain was perplexed that the explosion occurred aft of the ship’s widest point which gave rise to the notion the explosion might have been caused by a torpedo even though no submarine or torpedo trail had been spotted. Other theories suggested a coal bunker explosion or sabotage.
To commemorate the 100th anniversary of the loss of San Diego, the only major U.S. warship sunk in World War I, a 2-year project by the US Naval History and Heritage Command was launched in 2017 with the aim of mapping the wreck, assessing the wreck’s state of preservation, modeling its sinking, and uncovering the cause that likely sank it.
The USS San Diego Project
employed the help of underwater robotics, high-resolution 3-D images, and computer modeling to resolve the century-old mystery.