On August 6, 1945 the Japanese city of Hiroshima was the site of the first use in war of an atomic bomb (the second and, so far, last was at Nagasaki three days later). The bomb was dropped by a B-29 nicknamed 'Enola Gay' piloted by Col. Paul Tibbets, and was an uranium bomb. An estimated 70,000 persons were killed in the initial blast and firestorm, with perhaps another 30,000 perishing from radiation effects within the year. The long term death toll may have been twice that.
The bombings convinced the Emperor of Japan to signify to the government that he believed it was time for the war to end. Many today believe the bombing to have been cruel and unnecessary, since the Japanese Navy was completely destroyed already, and all overseas posts throughout the Pacific had already been conquered by the US forces. However, the Japanese military government prior to the Emperor Hirohito's statement had no intention of surrenduring. Their plan was for total defense of the homeland by all members of the armed forces and the civilian population, with the national slogan "Ten Million Die Together". It was estimated by the US Chiefs of Staff that American casualties in an invasion would probably top one million, and there was a strong possibility that a successful invasion would still not have ended the war. There was great support within the Japanese military for the plan that, in the event of defeat in Japan itself, the government would relocate to the Asian mainland, where Japan still had over one million soldiers under arms.
The United States and its allies liberated Europe in 1944, at which time the U.S. focus of the war shifted to the Pacific. The United States would accept nothing other than an unconditional surrender from Japan, which Japan refused. As the battles between the U.S. and Japan dragged on from island to island the American death toll continued to mount. The U.S. B.29 named Enola Gay dropped the first atomic bomb on Hiroshima on August 6, 1945 to leave the Japanese no alternative to that unconditional surrender, however they did not surrender. On August 9,1945 a second atomic bomb was dropped on Nagasaki which led to the surrender of the Japanese on August 14,1945. President Truman justified the use of the atomic weapon to save American lives, but it must be noted that neither the President nor the scientists involved in the creation of the atomic bomb (titled the Manhattan Project) never truely comprehended the destructive nature of the bomb.