Many interesting stories of hobby tunnel diggers. I remember a news story a few years ago, a "tech bro" type person had a tunnel project where a guy he hired died (or hospitalized?) due to unsafe working conditions. Ah yes, here's an article about it.

A Paranoid Tech Bro, a Homemade Nuclear Bunker, and a Shocking Death - https://www.washingtonian.com/2019/09/08/paranoid-tech-bro-h...