Eric Schlosser's 'Command & Control' is a fascinating and very readable look at nuclear accidents and almost-accidents. Recommended if you're interested in this area.
This is where I initially found the story of the tape mishap. Many more terrifying ones in there, especially the one about the B52 disintegrating and dropping a near armed nuclear warhead over North Carolina...
http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bom...