While many in Japan believe the bombings were unjustified. Many in the US believe the nuclear attack was necessary to end the war quickly. Theodore Van Kirk, a mission crew member, described the attack as a success. His biggest fear at the time, was getting too close to the nuclear explosion himself.

"That was our biggest worry--was getting away from the bomb. You know how do you get away from the bomb? You drop the bomb, if the bomb goes this way, you go this way, but you have to make a very rapid turn....so you're at 30,000 feet. He's at a 30, 60 degree bend, which is a very sharp angle for 329," he said.

Major Van Kirk and 11 of his comrades were responsible for dropping the world's first atomic bomb, codenamed "little boy" -- and killing some 140,000 people in one day. Van Kirk died last summer.

In earlier interviews with the veteran, he described his distaste for war and the use of atomic weapons. But he expressed no regret for dropping the world's first atomic bomb. To Van Kirk, the nuclear attack was necessary to end the war quickly. Without it, he said, the conflict would have led to even more casualties for all sides.