For anyone interested in this subject, check out "The Men Who Brought the Dawn", currently airing on the Smithsonian Channel. It's a fascinating documentary told by the men who flew the missions. I loved hearing their perspective on it. I had no idea how much authority Col. Tibbets had in mission planning.
[FWIW I'm starting this in the History forum rather than the TV forum because I hope to ignite a discussion about the atomic bombings rather than a discussion about the TV show.]