The museum starts before the bomb, with the story of the place itself. The hypocenter of the explosion was the Urakami district, which had long been a rustic and rather isolated suburb. After the 1920s that changed. The district was chosen as a site for munitions factories, and its population soared. A section of the museum called Events Leading up to the Nagasaki Atomic Bombing sets out the chain of historical developments behind the attack, and it aims to present them apart from the biases of the present day. The wider exhibition also looks back at the wars that formed the background, the conflict between Japan and China and then the Pacific War. Then comes the day itself. At two minutes past 11 a.m. on August 9, 1945, the bomb nicknamed Fat Man was dropped on Nagasaki. Its code name came from the United States, where Robert Serber chose it, after a character played by Sydney Greenstreet in the film The Maltese Falcon. A mushroom cloud rose to about 45,000 feet, roughly 14,000 meters, above the city. A model of Fat Man is among the displays, so you can see the shape of the weapon that did this.