
According to that bastion of truth, Wikipedia:
Centralia is a borough in Columbia County, Pennsylvania, United States. Its population has dwindled from over 1,000 residents in 1981 to 12 in 2005 as a result of a 40-year-old mine fire burning beneath the borough. Centralia is now the least-populous municipality in Pennsylvania.I dare anyone to get more hardcore than a mine fire burning underneath a town. For forty freaking years. The government has basically forced the residents out, and only a handful remain - more or less out of protest - for now, anyway. It has no zip code, any more. It is noplace, nowhere - a true ghost town (and, coming from Nevada, I certainly have experience with ghost towns).
Centralia, PA has a fire burning below its streets. Badass.