http://en.wikipedia.org/wiki/Little_BoyThe bombing of Hiroshima
The bomb was armed in flight
9600 m (31,000 feet) above the city, then dropped at approximately 8:15 a.m. (JST). The detonation happened at an altitude of 580 m. With a power of 13 to 16 kilotons (estimations vary), it was less powerful than "Fat Man," which was dropped on Nagasaki (2123 kt). The official yield estimate of "Little Boy" was about 15 kilotons of TNT equivalent in explosive force, i.e. 6.3 × 1013 joules = 63 TJ (terajoules)[4]. However, the damage and the number of victims at Hiroshima were much higher, as Hiroshima was on flat terrain, while the hypocenter of Nagasaki lay in a small valley.
Approximately 70,000 people were killed as a direct result of the blast, and a similar number were injured. A great number more would later die as a result of nuclear fallout and cancer.[5] Unborn babies died or were born with deformities.[6]
The success of the bombing was reported with great enthusiasm in the United States. See Atomic bombings of Hiroshima and Nagasaki for discussion of contemporary opposition to the bombings, on both moral and military grounds.
