fire

By some accounts, Hell on Earth is located directly below Centralia, Pa.: Smoke rises from the cracked ground, smoldering sinkholes open without warning, and what is left of the town’s abandoned houses and surrounding woodlands is scorched and covered in a layer of smelly sulfur. Once a productive mining town in eastern Pennsylvania’s valuable anthracite coal region, Centralia has been reduced to a smoky ghost town, lacking even a zip code, by an underground coal fire that has been burning for nearly 50 years.

What makes a fire burn? In addition to fuel (such as wood or paper) and heat, fires need oxygen. If there isn’t enough oxygen in the atmosphere, combustion simply won’t happen.