Nuclear weapon
By August 1945, the Manhattan Project had built three nuclear fission weapons. Two of the bombs were used by the United States to attack the cities of Hiroshima and Nagasaki in Japan. People from the Manhattan Project believe that around 105,000 people were killed and 94,000 were hurt when the bombs were used. Medical professionals later came to believe that more than 225,000 people died when everyone who was affected after long periods of time has been counted. Japan announced its surrender after the atomic bombings of Hiroshima and Nagasaki.