One particular Pennsylvania ghost town sits atop a fire that hasn't stopped burning for decades -- and you can still visit ...

“Pennsylvania didn’t have enough money ... coal laced by interconnected airways—a perfect setting for a coal fire. The Centralia fire probably got going in May 1962, when local sanitation ...

And how this fire started still remains a mystery. But chemistry can help explain why it's still going. Centralia, Pennsylvania sits atop a few of the biggest coal deposits in the world.