Centralia

Made famous for the underground coal mine fire which has been burning beneath the borough since 1962. Population is down to 5 people. The entire town has been claimed under eminent domain, with the remaining residents allowed to live there until they die and then their homes revert to the state. The fire started in a landfill. How it started is still being debated but the underlying cause is known. The borough was required by law to install a fire-resistant clay barrier between each layer of the landfill. They didn't. A landfill fire hit the coal, and has been burning since. Pennsylvania doesn't plan on extinguishing the fire, just letting it burn for the next 250 years. Which probably is not the smartest decision, but they have been kicking the can down the road for decades.