<human>:  When did the Lusitania sink?
<bot>: The RMS Lusitania was sunk by a German U-boat on May 7, 1915. It was a British ocean liner, and it was torpedoed by a German submarine in the Atlantic Ocean off the coast of Ireland. The ship was en route from New York City to Liverpool, England, when it was attacked by the German submarine U-20. The ship sank in 18 minutes, taking 1,198 lives with it. The sinking of the Lusitania was a major event in the United States and United Kingdom during World War I.