Some things that might be cause for reason:
1. Earthquake prone, systems could be unstable due to the integrity of the rock walls being compromised.
2. Uncharted caves, when it comes to public knowledge of such systems existing.
That Mammoth Cave correlation is jaw-dropping to me, quite the "coincidence."
(Weren't there prominent families that lived in the areas on top of the mammoth cave system that actually took the time to tunnel in and re-fortify system walls for transportation of product and people back in the late 1800's?)
Do these images look similar? The top is a map of Missing 411 cases. The bottom is a map of America’s cave systems. Caves seem to play an interesting roll in some of these disappearances. The Mammoth Cave system in particular had caught my interest. : Missing411
[–] 21152637? 0 points 1 point 1 point (+1|-0) ago
DUMBs all over the place. Built with trillions stolen from us.