Lewis estimates that the bombing of Hiroshima and Nagasaki, to the extent that it induced Japanese surrender, saved the lives of roughly 30 million people.

What would have happened if Hiroshima was never bombed?

The bombs brought a quick end to the war. Without the bombs, the war would have likely dragged on for at least another year, perhaps longer. The Allies' plan for Japan was called Operation Downfall and consisted of two parts, Operation Olympic and Operation Coronet.

Were there survivors in Hiroshima?

More than 75 years after the U.S. dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on Aug. 6 and Aug. 9, 1945, roughly 136,000 people are living with the memories—and effects—of the disasters. In the U.S., specifically, there are believed to be just under 1,000 survivors.