Yeah going underground in old mines is bad news bears for all involved. Say you go down and something does go wrong, there's no escape. You'll either be crushed or drown before rescuers could dig down to you. Some people still do it but that is the risk you run and you never know when a collapse or something will happen. I find exploring under ground in tour mines or caves awesome personally but I'd never go into abandoned one just because of the risk. Unless it was like in fallout then I'd say screw it and hunker down in my new vault