2014 Event Swedish officials release a photo of U-boat tracks along the sea floor as proof that a foreign submarine breached the nation�s waters; the search began after the military detected Russian-language distress calls and spotted an unidentified vessel 2012 Event The U-550, a sunken German U-Boat, is discovered off the cost of Massachusetts 1943 Event Admiral Donitz stops U-boat in Atlantic Ocean 1942 Event Nazi U-boat sinks American cargo ship at mouth of Mississippi River 1942 Event German U-boat shells at Antillian oil refinery 1941 Event German U-boat torpedoes U.S. destroyer Kearney 1941 Event 1st U.S. ship sunk by a U-boat (SS Robin Moore) 1939 Event German U-boat torpedoes passenger ship 1939 Event German U-boat torpedoes tanker Sliedrecht near Ireland 1939 Event German U-boat sinks British passenger ship Athenia 1918 Event Dover Patrol overthrows Germany U-boat in East Sea
