The atomic bombings of Hiroshima an Nagasaki were nuclear attacks at the end of World War II against the Empire of Japan by the United States at the order of U.S. President Harry S. Truman on August 6 and 9, 1945. After six months of intense firebombing of 67 other Japanese cities, the nuclear weapon "Little Boy" was dropped on the city of Hiroshima on Monday, August 6, 1945, followed on August 9 by the detonation of the "Fat Man" nuclear bomb over Nagasaki. These are to date the only attacks with nuclear weapons in the history of warfare.