An underground fire that has been burning for 50 YEARS

Pictures: Centralia Mine Fire, at 50, Still Burns With Meaning

The worst U.S. mine fire, in Centralia, Pennsylvania, passed its 50-year mark last year. As coal-powered development spreads globally, so does the risk of underground fire.

National Geographic

The Centralia blaze, still burning more than 50 years after it began, ranks as the worst mine fire in the United States. But it is by no means the only one. More than 200 underground and surface coal fires are burning in 14 states, according to the U.S. Department of Interior's Office of Surface Mining Reclamation and Enforcement.

And with worldwide demand for coal surging, especially in industrializing nations such as India and China, mine fires have emerged as a global environmental and public health threat. Thousands of coal fires rage on every continent but Antarctica, endangering nearby communities. The blazes spew toxic substances such as benzene, hydrogen sulfide, mercury, and arsenic, as well as greenhouse gases like methane and carbon dioxide.