On December 7, 1941, the Empire of Japan launched a surprise air raid on the U.S. Navy base at Pearl Harbor in Hawaii. The attack resulted in the deaths of more than 2,300 Americans, with some sources reporting 2,400 fatalities. This devastating assault marked a turning point in history, as it prompted the United States to formally declare war against Japan the following day, leading to its entry into World War II. The attack came after years of escalating tensions between the U.S. and Japan, driven by Japan's military expansion in Asia.