I found a fairly good rundown of the terrible events of December 7, 1941 at Infoplease: Pearl Harbor Remembered.
Excerpt:
Dec. 7, 1941—at five minutes to eight o’clock, 183 Japanese warplanes ruined a perfectly fine Sunday morning on the island of Oahu in Hawaii. The first attack wave had reached the U.S. Pacific Fleet stationed at Oahu’s Pearl Harbor and for all intents and purposes, World War II began for the United States
Although the U.S. military forces in Pearl Harbor had been recently strengthened, the base was not at a state of high alert. Many people were just waking when the first bombs were dropped. No one was prepared to do battle.