I am taking off to go hunting, but I'd be happy to talk about energy, mining and other related topics in depth in another thread later. there are also some other informed individuals on these topics who are members here. You could get at least 3 perspectives on wind energy and I'm sure that many on coal mining in general.
There are several key reasons for mining accidents, some structural or geology related reasons, some caused by human error....explosions to to improper venting of combustible or noxious gases that collect in mines.
When I have more time, I'll try to explain some of it better.
"Silence is Golden. Duct Tape is silver"