Destruction per plane: the only thing to come close to matching Hiroshima is Nagasaki. (If that bomb had been dropped on the intended target, rather than a random opening in the clouds, the casualties would have been as great as Hiroshima.) It is worth noting that in all three instances, the brick and metal structures largely withstood the blasts, but they were gutted by the ensuing firestorms that consumed a wide area of each city leaving only smoldering ashes. Many tons of ash and soot were sucked upward and injected into the stratosphere. If the fire/atomic bombing had not ceased, it might have catastrophically disrupted the global climate.

(One might speculate that the Ukraine famine of 1946 was in part due to the dozens of firestorms in 1945. I wish the nuclear winter modelers would run that true-history scenario.)