On April 26, 1986, a turbine test on one of the reactors at the Chernobyl nuclear power station went horribly awry, leading to a series of explosions that spewed massive amounts of radioactive material into the atmosphere. The accident, which the Soviet authorities attempted to cover up, initially claimed only 31 lives: two plant workers who died in the blasts, a third who reportedly keeled over of a heart attack and 28 first responders who contracted acute radiation syndrome during the frantic early stages of the cleanup. However, Chernobyl also unleashed a thyroid cancer epidemic and likely caused additional cancer cases as well. In 2005, a United Nations-backed panel calculated the eventual death toll at up to 4,000, whereas other organizations put this number significantly higher. For perhaps centuries to come, an exclusion zone, set up around the plant following the forced evacuation of tens of thousands of area residents, will be off limits to human habitation.