Another is lost in the mud somewhere off the coast of Georgia near Tybee Island.
I saw the headline, and thought that was the one they were talking about. But it is more marsh than swamp there. Looking back, the Air Force dropped quite a few H-bombs in the southeast that didn't explode (in one case, only one of the four safeties remained on safe when the unexplodeded device was recovered) during the early civil rights era. Not including the two bombs they set off in Mississippi during the LBJ era, ending real resistance to the movement by the state government.