Fat Man, the second atomic bomb the United States dropped on Japan during World War Two, was detonated on this day in 1945. The development of Fat Man, along with the first bomb detonated over Hiroshima, Little Boy, led to the creation of many of Russia’s bombs, including the Joe-1 and the eventual Tsar Bomba, the most powerful bomb created in the history of mankind. Fat Man, detonated over the industrial and port city of Nagasaki, killed more than 35,000 people when it exploded early in the morning, killing thousands more from burns sustained by the explosion, and hundreds more from the immense amount of radiation released upon impact. Fat Man and Little Boy were some of the major forces, along with the Soviet declaration of war, that led to the surrender of Japanese forces to the Allied Powers. Japan was, by 1945, the only Axis Power still at war with the Allies, as the Italians had surrendered in 1942, and later the Germans as well earlier in May of 1945. Following the destruction of their cities and the threat of more bombings, as well as a naval invasion by the Allies, the Japanese announced their surrender on August 15th, 1945, and signed the treaty by September 2nd. Fat Man remains the second and last nuclear bomb used in warfare, and its design was retired by 1950.