The first nuclear bomb meant to kill humans exploded over Hiroshima, Japan, on August 6th, 1945. The last nuclear bomb was dropped three days later, on the 9th August 1945, on Nagasaki.
The bomb that was used for Nagasaki on August 9th 1945, was called 'Fat Man'. This weapon weighted about 4500 kilograms, and was approximately 3 meters and 20 centimeters long. It had an explosive capacity equivalent to around 20,000 tonnes of higher explosives. Almost all living things, which included humans and animals, were burned to death as a result of the bombing.
The survivors and their children suffered horrific forms of radiation sickness long after the explosion. The bomb dropped on Nagasaki was also the last major act of World War II, before the Japanese surrendered.
Estimates of people who died in Hiroshima and Nagasaki are above 1,40,000. People continued to suffer radiation diseases for more than two generation. This event is the most inhuman act in human history.