It's a decently well-known phenomenon. https://en.wikipedia.org/wiki/Coal-seam_fire https://en.wikipedia.org/wiki/Coal-seam_fire For example: https://en.wikip

It's a decently well-known phenomenon. https://en.wikipedia.org/wiki/Coal-seam_fire https://en.wikipedia.org/wiki/Coal-seam_fire For example: https://en.wikipedia.org/wiki/Centralia_mine_fire https://en.wikipedia.org/wiki/Centralia_mine_fire -- Started burning in 1962. Still burning today and on track to burn for another 250 years.