I was only four years old (goin’ on five) when this happened. The people in the foreground to the right of center haven’t yet noticed what was happening in the background. Twenty thousand TONS of TNT equivalent was exploding in the second nuclear blast in wartime history. Nagasaki was being obliterated; the date was August 5, 1945. Three days earlier a similar bomb had destroyed Hiroshima.
Since that terrible time the world has argued whether the bombing with nuclear weapons was justified. The argument by the United States was that it saved the lives of thousands, perhaps millions of soldiers and civilians because it forced the recalcitrant Japanese warlords to surrender, which would not have happened if the US had only fought with “ordinary weapons.” The overwhelming terror of the individual atomic bombs convinced the Japanese that they simply had no choice.
What fascinates me about the photograph is that something so overwhelmingly powerfully destructive can be happening and not be noticed immediately. (By clicking on the picture you can see it a bit larger.)