A coal mine fire is an underground fire that occurs in coal mines, often ignited by spontaneous combustion or external sources. These fires can burn for long periods, sometimes for decades, and are difficult to extinguish due to the confined space and the presence of flammable materials. The impact of a coal mine fire can be severe, leading to the release of toxic gases and the destruction of valuable resources. Notable examples include the Centralia mine fire in Pennsylvania, which has been burning since 1962, causing the town to be largely abandoned due to safety concerns.