Wasn't Nagasaki a secondary target?
Yes, it was on a list as a secondary target. But once go-ahead was given to drop Fat Man, and the primary target was obscured, the decision to drop on Nagasaki was automatic. They were ordered to have a visual drop to proceed. Many feel there was no need to drop a second nuke, and there continues to be much controversy about it. The Japanese were going down in defeat, and only mere days had elapsed since the first atomic drop. We would have been better off seeking a true military target, rather than the heart of Japan's Christian community in a civilian city.