In May of 1962, a fire was started in the town landfill, next to the Odd Fellows Cemetary in order to clean up the area before a Memorial Day Celebration.
This fire was authorized by the town council, and was ignited by members of the local Volunteer Fire Department. All of the trash was piled up in a corner of the landfill and ignited. After the fire had burned most of the trash, it was extinguished. Oddly, though, it kept re-igniting itself as the weeks passed.
What the members of the town did not realise was that there was an un-sealed abandoned coal mine shaft beneath the pile. The trash fire ignited a coal seam beneath the earth, and continues burning to this day.
Beneath Centralia and surrounding areas lies a rich deposite of anthracite coal; very hard and compact, which burns slowly at a high temperature. Since the initial fire in 1962, the underground mine fires have spread some 400 acres, forcing the evacuation of homes in Centralia.
At its peak, Centralia had more than 2,000 residents. The Borough of Centralia had, at one point, "seven churches, five hotels, twenty-seven saloons, two theaters, a bank, and a post office, fourteen general stores, and a post office".
In 1984, Congress allocated approximately $42 million for relocation of Centralia's residents. Most took the offer and moved to surrounding areas.
According to the 2004 census, there were only 18 people still remaining in Centralia.
All that is left today is a few lone homes, civic buildings, and barren roads which lead into empty feilds.
Here's a link to Wikipedia for more information.