"[...]the humidity in the room, which had to be critically maintained at 60 percent — deviation either way could have resulted in an explosion large enough to destroy the entire base, not to mention the mountain that housed it and much of the surrounding area."

I'm going to assume that anything large enough to destroy the surrounding mountain would require at least one of the missiles/warheads to go (thermo-)nuclear. But my understanding is that actually achieving the Big Bang is really rather difficult to do intentionally, let alone by accident - at worst you have a few kton fizzle. So how is a small change in humidity able to trigger one or more of these weapons? (And, if one did successfully trigger, is it possible that it could daisy-chain the rest, or would they be torn apart before achieving supercritical geometry?)

Then again, I guess it's maybe possible that the supplies of conventional munitions and maybe nasty missile/rocket propellants could do some major damage, but a whole mountain?