About 29 years ago, as an Air Force B-36 bomber flew over New Mexico, a hydrogen bomb weighing 42,000 lbs. somehow got loose, tore away the plane's bomb-bay doors and plunged to earth, landing in the desert about ten miles from Albuquerque. The Mark 17, an estimated ten-megaton monster hundreds of times more powerful than the weapon that leveled Hiroshima, was one of the largest bombs in the U.S. arsenal. It did not set off a nuclear explosion, but it did leave a crater 24 ft. across.
In reporting on the little-known incident last week, after having sifted through documents newly...