The United States remains the only nation to have used atomic bombs as weapons against an enemy. Little Boy, an untested uranium weapon, was dropped on Hiroshima, Japan, on an August Monday in 1945.
Three days later on August 9, Fat Man, an implosion device with a plutonium core like that in the Trinity test, was dropped from the B-29 Bockscar. The atomic bomb exploded, with a yield equivalent to 21 tons of TNT, 1800 feet above Nagasaki. Cloud cover had obscured the primary target that day sixty-five years ago; Nagasaki was the back-up plan.
Half the eventual deaths from each explosion occurred on the first day. Six days after the Nagasaki bombing, Japan announced surrender.