This involved the Goldsboro crash where a B-52 flying a 24-hour mission with nuclear weapons was found to have sprung a fuel leak during an aerial refueling. The crew were told to fly around a bit to burn off fuel before landing, but the leak had gotten worse, and they lost something like 37500 pounds of fuel. When this was reported, the crew were cleared for an emergency landing.
As they began their descent, they started to lose control of the plane, and eventually, the right wing folded up, and control was lost. As the plane went out of control, the aircraft's 2 x Mk.39 warheads had tumbled out. If I recall one weapon was, for most intents and purposes, armed, except that a high voltage component failed to work (which is quite a relief).
What I found was, while finding data on the crash (mostly YouTube videos), and in the video, there was an image like this one. Because the document looked official, and the 24 megaton yield was well beyond the normally listed figures, I did an additional search and found this image on a site.
Since the document is not classified, why the discrepancy in yield (provided that's not classified).