On Sunday, December 7, 1941, at 7:55 a.m., approximately 355 aircraft from the Japanese Imperial Navy attacked American military installations and the naval base at Pearl Harbor on the island of Oahu, Hawaii, without warning. In less than two hours, the attack was over, and the Japanese returned home almost unscathed to a hero's welcome. Twenty four hundred and three Americans were killed, and eleven hundred seventy eight were wounded. Eight American battleships, four destroyers, three cruisers, many other smaller ships, and three hundred forty seven United States aircraft were destroyed or damaged. This unprovoked sneak attack prompted the United States to declare war on the Japanese Empire on December 8, 1941. On August 6, 1945, Hiroshima, Japan, became the target of the first atomic bomb employed over a populated area. On August 9, 1945, a second bomb was dropped over the city of Nagasaki, Japan. On August 15, 1945, Japan unconditionally surrendered to the allies.