Check the dates in history books when the these two bombs were dropped. Little boy was dropped on 6th Aug 1945 and Fat man was dropped on the 9th of August 1945.

Japan finally surrendered on the 15th of August.

Do you guys really think, dropping of the second bomb on Nagasaki was really required. Historians differ in their interpretations but the dates tell us the real story.

Despite being fully aware of the after effects of and atomic blast, what was the justification of deploying another bomb within 72 hours of the first one?

Note that Little Boy was Uranium 235 and Fat Man was Plutonium. It is evident that US seized a good opportunity to test Plutonium at the expense of thousands of Japanese lives.