I think cities and rural areas all over America are involved with these tunnels. And I think that's what causes "sink holes":

https://4.bp.blogspot.com/-lVW0ONT-BWA/TmyI90HqymI/AAAAAAAABGg/fWS8NyTvFvQ/s1600/sinkhole_01.jpg

And: https://i2-prod.mirror.co.uk/incoming/article1743868.ece/ALTERNATES/s1227b/Sinkholes%20along%20the%20shore%20line%20of%20the%20Dead%20Sea.png

I think cities and rural areas all over America are involved with these tunnels. And I think that's what causes "sink holes".

I think cities and rural areas all over America are involved with these tunnels.