On December 7, 1941, Japan launched a surprise attack on the U.S. naval base at Pearl Harbor in Hawaii. Over 2,300 Americans were killed in the bombing that destroyed or damaged 19 U.S. naval vessels including eight battleships. The attack forced the U.S. into World War 2 by breaking the backbone of the American Pacific fleet and ending a policy of isolationism. Congress declared war on Japan the day after the "date which will live in infamy".