The U.S. Navy lost an entire ship and all of its crew and has no idea how it happened!
The U.S.S. Cyclops was one of four Proteus-class colliers built for the U.S. Navy in 1910.
The ship was the second one named after the Greek mythical giants.
In 1917 the ship was commissioned due to the start of World War I and her captain, George Worley, was promoted to full captain.
Sometime after March 4, 1918 the ship and her entire crew of 306 crew and passengers disappeared without a trace.
They found out later that Worley was a German who had changed his last name.
They also learned that he was quite the brutal ship captain and had an unstable and changing personality. All of his associates were known to be German or of German descent.
Some speculate that he was sympathetic to the Germans and may have done something awful to his own ship.
Nonetheless, the loss of the U.S.S. Cyclops is the single largest loss of life in the U.S. Naval history that wasn't involved in direct combat. May she rest in peace.