Pearl Harbor

Pearl Harbor, inlet of the island of Oahu, Hawaii, 10 km (6 mi) west of Honolulu, and the site of one of the principal naval bases of the United States.

The United States government first obtained exclusive use of the inlet and the right to maintain a repair and coaling station for ships here in 1887. The harbor was surveyed then and later, but improvements were not begun until after the United States annexed the Hawaiian Islands in 1898. In 1911 the work of dredging a wide channel from the sea, across the sandbar and coral reef at the mouth of the harbor, was completed. The channel is 11 m (35 ft) deep, and the harbor has a maximum depth of 18 m (60 ft), making the harbor available to the largest naval vessels.

Early in the morning of December 7, 1941, Japanese submarines and aircraft carrier-based planes attacked the U.S. Pacific fleet at Pearl Harbor. Nearby military airfields were also attacked by the Japanese planes, which numbered about 350. Eight American battleships and 13 other naval vessels were sunk or badly damaged, almost 200 American aircraft were destroyed, and approximately 3,000 naval and military personnel were killed or wounded. In addition 68 civilians were killed and 35 wounded. The Japanese lost 29 aircraft, a large submarine, and 5 midget submarines in the attack. The attack marked the entrance of Japan into World War II (1939-1945) on the side of Germany and Italy, and the entrance of the United States on the Allied side.

On November 25, 1941, a Japanese naval task force had set off from Tankan Bay in the Kuril Islands. The task force consisted of two battleships and six aircraft carriers, with supporting surface and submarine units. The final code to launch the attack, “Climb Mount Niitaka,” was radioed to the Japanese task force commander on December 2, 1941. Concealed by a favorable weather front, the task force reached a position 370 km (230 mi) north of Oahu on the morning of December 7.

Two Japanese reconnaissance planes flew over Pearl Harbor at about 6 am, and a midget submarine penetrated the inner harbor. They confirmed Japanese intelligence reports that the bulk of the United States fleet was at its base. American Navy and Army units were not on a wartime alert. Military planes parked in compact rows presented an excellent target to the invading Japanese planes, which arrived over Oahu at 7:50 am. The bulk of the American planes were destroyed on the ground in the first minutes of the attack. The Japanese planes then turned against fleet units moored in the harbor, which they bombed for nearly two hours.

Four U.S. battleships—the Arizona, California, West Virginia, and Oklahoma—were sunk; the Nevada was beached in sinking condition. Three other battleships, three cruisers, a seaplane tender, and a repair ship were damaged. Also sunk were three destroyers, a target ship, and a minelayer. The Japanese attack, however, failed to destroy workshops and repair facilities, enabling the U.S. Navy to repair and put back into service some of the damaged vessels. The attack also did not target fuel storage depots nor the submarine base, and missed three American aircraft carriers that were at sea. Nevertheless, the losses sustained by the U.S. fleet on December 7 and the loss of two British ships—the Prince of Wales and Repulse—on December 10 gave the Japanese temporary control of the western Pacific.

Soon after the attack, U.S. President Franklin D. Roosevelt appointed a commission of inquiry to determine whether negligence had contributed to the success of the Japanese raid on Pearl Harbor. The commission’s report found the naval and army commanders of the Hawaiian area, Rear Admiral Husband E. Kimmel and Major General Walter C. Short, guilty of “derelictions of duty” and “errors of judgment”; the two men were subsequently retired. Other later inquiries, however, differed in their conclusions. The Congress of the United States, in an effort to dispose of the controversy, decided on a full, public investigation after the war.

The bipartisan congressional committee opened its investigation in November 1945. Testimony from many people reviewed all known information about the attack on Pearl Harbor. The committee reported its findings in July 1946. It placed the primary blame on General Short and Admiral Kimmel, who, however, were declared guilty only of errors of judgment, and not of derelictions of duty. The committee recommended the unification of the U.S. armed forces, which occurred the following year. The USS Arizona National Memorial, standing above the remains of the battleship in Pearl Harbor, commemorates the Americans who died in the attack.