Excerpt: "The Gates of Hell crater was created in 1971 when a Soviet drilling rig accidentally punched into a massive underground natural gas cavern, causing the ground to collapse and the entire drilling rig to fall in. Having punctured a pocket of gas, poisonous fumes began leaking at an alarming rate.

To head off a potential environmental catastrophe, the Soviets set the hole alight, figuring it would stop burning within a few weeks."