The mushroom cloud caused by the detonation of the "Fat Man" bomb during the atomic bombing of Nagasaki, Japan in 1945, rising approximately 18 kilometres (11 mi) above the hypocenter.
On the morning of August 9, 1945, the U.S. B-29 Superfortress Bockscar flew towards its primary target Kokura, but a 7/10 cloud cover had obscured the city, prohibiting the visual attack required by orders. They flew on to Nagasaki, which was likewise obscured. At 11:01, a last minute break in the clouds allowed the bomb to be dropped over Urakami Valley, which protected much of the city from the bomb's effects.Photo credit: United States Army