View source for Japanese air attack against the US fleet at Pearl Harbor

In the early morning hours of 7 December 1941, fighter planes and bombers took off from Japanese aircraft carriers and attacked the US Pacific fleet at Pearl Harbor naval base in Honolulu, Hawaii, killing thousands of sailors and civilians and nearly crippling the US Navy. This unprovoked act of military aggression by the Empire of Japan forced the United States to become a combatant in WWII and opened a new front–the Pacific Theater–in a global war pitting Axis powers against Allied nations.