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 and 9 in 2007, as a result of a mine fire burning beneath the borough since 1962. Centralia is now the least-populous municipality in Pennsylvania, with four fewer residents than the borough of S.N.P.J. Courtesy of Centralia Pennsylvania on WikiPedia. read more about this by clicking here.