Chernobyl
In terms of scale and casualties, the Chernobyl nuclear disaster was the worst nuclear power plant accident in history. On April 2, 1988, an explosion occurred during a routine test at the Chernobyl Nuclear Power Plant. Fire and plumes of smoke spewed out radioactive particles into the sky which traveled over the western USSR territory and the rest of Europe. Now, this area is strictly off-limits as the radiation levels are deadly.