system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:with underground fires like Centralia or the place in Virginia which inspired Silent Hill, why can't they be put out by just pumping lots and lots of water into the mine?

Surely this would, if successful, save loads of coal from burning and polluting, and could then still be mined in the future?
gpt
Imagine the coal coating the inside of an uncleaned chimney is on fire and you're standing on the roof.  
Pouring water down the chimney to drown the fire would miss a lot of the fire on the way down.  So you'd have pour enough water to flood the entire house and let the rising water put out the fire in the chimney.   
However the house has its windows open.       
    
So the water going into that cavern could end up in a neighboring cavern.