Beginning in early 1915 during World War I, the German Navy began unrestricted submarine warfare in the waters around the British Isles. Mostly, they were more threatening than damaging, making shipping lines more difficult and creating generally anxiety about German submarines, known as U-boats. Then, on May 7, 1915, the German U-boat U-20 was off the Irish Coast and saw the RMS Lusitania coming at it. The Lusitania was one of the greatest ships of the Cunard Line and was a large passenger ship loaded with many transatlantic passengers on its route from New York to Liverpool. U-20 shot one torpedo that hit the Luistania in the starboard side. The Lusitania went down in just about 18 minutes. Due to falling over on its starboard side, most of the ship's lifeboats could not be deployed. In total, 1200 people would die on the Lusitania after it was sunk. This fact caused extreme outrage from Britain, although not all of it was directed at the Germans as it was at the Cunard Line and the Lusitania's captain. The real shock was in America, as a handful of American citizens died, and the sinking of the RMS Lusitania caused American sentiment to fall firmly against the Germans.