U.S.S. Arizona survivor Lou Conter and daughter Louann Daley exit the Arizona Memorial a memorial service for the 70th anniversary of the attack on the U.S. naval base at Pearl Harbor on the island of Oahu on December 7, 2011in Pearl Harbor, Hawaii. On the morning of December 7, 1941 a surprise military attack was conducted by aircraft of the Imperial Japanese Navy against the U.S. Pacific Fleet being moored in Pearl Harbor, marking the entry of the U.S. in World War II. More than 2,400 people were killed and thousands wounded, with dozens of Navy vessels either sunk or destroyed.