From Wikipedia.
The USS Eagle 56 (PE-56) was a U.S. Navy World War I-era patrol boat that remained in service through World War II. On 23 April 1945, while towing targets for U.S. Navy bomber exercises off the coast of Maine, it was sunk by German U-boat U-853.
Only 13 of the 62 crew survived
The loss was classified as a boiler explosion until 2001, when historical evidence convinced the Navy to reclassify the sinking as a combat loss due to enemy action. The Eagle was the second to last Navy warship to be sunk by German during the war.
It was one of 60-Eagle Class patrol craft built by Henry Ford late in World War I as submarine chasers, none of which saw action. Unpopular due to their poor sea handling, only eight remained in service by the time WW II began for the United States.
It was the second to last U.S. warship to be sunk by Germany during WW II.
--GreGen