Three months after victory in Europe, the first atomic explosion used in war hastened the end of World War II in the Pacific and ignited the fears of world destruction. With the explosive force equivalent to 20,000 tons of TNT, the"Little Boy" bomb dropped over Hiroshima on Aug. 6, 1945, was small in comparison to the megatonnage of today's superpower nuclear arsenals.
The city's utilities, communications and transportation systems were shattered. More than 90 percent of Hiroshima's doctors and nurses were killed and only 3 of the 45 hospitals remained usable. About 7,000 of the 24,000 Japanese military personnel in Hiroshima were killed. The dead almost certainly included 23 American prisoners of war being held at the imperial headquarters about 900 yards from ground zero.