At 7:55 a.m. Hawaii time, a Japanese dive bomber bearing the red symbol of the Rising Sun of Japan on its wings appears out of the clouds above the island of Oahu. A swarm of 360 Japanese warplanes followed, descending on the U.S. naval base at Pearl Harbor in a ferocious assault. The surprise attack struck a critical blow against the U.S. Pacific fleet and drew the United States irrevocably into World War II.
With diplomatic negotiations with Japan breaking down, President Franklin D. Roosevelt and his advisers knew that an imminent Japanese attack was probable, but nothing had been done to increase security at the important naval base at Pearl Harbor. It was Sunday morning, and many military personnel had been given passes to attend religious services off base. At 7:02 a.m., two radar operators spotted large groups of aircraft in flight toward the island from the north, but, with a flight of B-17s expected from the United States at the time, they were told to sound no alarm. Thus, the Japanese air assault came as a devastating surprise to the naval base.