August 9, 1945
The Fat Man, the second of two atomic bombs, is dropped on Japan
Though Nagasaki had been home to a major naval fleet during the late 1800s and early 1900s, it was largely populated by civilians during WWII. At the time the bomb fell, 250,000 of the 263,000 in Nagasaki were residents; 9,000 were soldiers and the remainder were POWs or conscripted workers (slave laborers). The bomb killed between 39,000 and 80,000. Half of those killed died as a result of the explosion while the rest died of injuries or radiation sickness.
Read more about the choosing of targets and the injuries left by the bombs in a previous post on Hiroshima.