Dear Matthew Alice: I lived in Pennsylvania in the 1960s. One of the things that I remember about the place is that there were underground coal fires that had been burning for years. Have they been put out by now? — Jeannette, Solana Beach
Pennsylvania smolders on. So do West Virginia, Colorado, and other coal-rich areas. The town of Centralia, in east-central Pennsylvania, sits on a network of mine tunnels that have been burning for 30 years. The feds estimate there’s enough coal left to keep things warm for 1000 more. It probably started as a dump fire, which ignited a coal seam. Big subterranean coal fires are virtually impossible to put out. Pennsylvania has about three dozen going right now.