The Centralia mine fire is an underground coal fire that has been burning since 1962 in Centralia, Pennsylvania. It started when a fire ignited in a coal mine, possibly due to improper landfill burning. Over the years, the fire spread through the extensive network of coal seams beneath the town, making it unsafe for residents. As a result of the fire, the population of Centralia has drastically decreased, with most residents relocating due to health concerns and the risk of subsidence. The government eventually declared the area unsafe, leading to the abandonment of the town and the demolition of many buildings.