The Mushroom Cloud over Hiroshima, Japan
The mushroom cloud rising over Hiroshima, Japan. The city of Hiroshima was the target of the world's first atomic bomb attack at 8:16 a.m. on August 6, 1945. The cloud rose to over 60,000 feet in about ten minutes.
About 30 seconds after the explosion, the Enola Gay circled in order to get a better look at what was happening. By that time, although the plane was flying at 30,000 feet, the mushroom cloud had risen above them. The city itself was completely engulfed in a thick black smoke.
Source: National Archives