60 years ago the most horrific weapon known to man, the nuclear bomb, was used against the Japanese city of Nagasaki. The cost, in terms of civilian lives lost as a result of using such a weapon, was weighed against the likely much higher number of lives that would be lost in a ground battle for mainland Japan. An equation I would not want to try and solve nor one that I can second guess. I do know that we need to continue to strive to ensure such weapons are never used again.
This before and after picture of downtown Nagasaki says more than mere words could ever say regarding the total destructive power of such a weapon.