Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet. The attack on Pearl Harbor by the Empire of Japan on December 7, 1941 brought the United States into World War II.
On the morning of December 7, 1941, aircraft and midget submarines of the Imperial Japanese Navy began a surprise attack on the U.S. under the command of Admiral Isoroku Yamamoto. Despite long-standing assertions that this attack could have been predicted and prevented by the United States Military, the U.S. forces at Pearl Harbor appeared to be utterly unprepared, and the attack effectively drew the United States into World War II.
At 6:09 a.m. on December 7, the six Japanese carriers launched a first wave of 183 planes composed mainly of dive bombers, horizontal bombers and fighters.[4] The Japanese hit American ships and military installations at 7:55 a.m. The first wave attacked military airfields of Ford Island. At 8:30 a.m. a second wave of 180 Japanese planes, mostly torpedo bombers, attacked the fleet anchored in Pearl Harbor. The battleship Arizona was hit with an armor piercing bomb which penetrated the forward ammunition compartment, blowing the ship apart and sinking it within seconds. Overall, nine ships of the U.S. fleet were sunk and twenty-one ships were severely damaged. Three of the twenty-one would be irreparable.
Twenty-nine Japanese planes were brought down by the defences at Pearl Harbour during the attack that lasted for two hours. Midget submarines were also used in the attack and one managed to get into Pearl Harbour itself - only to be sunk by USS Monaghan.