Topographical map of Nagasaki, Japan, made as part of the United States Strategic Bombing Survey (USSBS). The map was created after a US bomber dropped the Fat Man atomic bomb on the city on 9th of August 1945. The bomb caused enormous destruction; it killed over 70,000 people and forced Japanese forces to surrender to Allied forces a few days later. The USSBS report was produced to study the aerial effects of bombing carried out in German-occupied Europe and Japan during World War Two, as well as for the strategic future planning of the armed forces.