The document discusses the Chernobyl disaster, the worst man-made disaster in history. On April 26, 1986, a explosion occurred at the Chernobyl nuclear power plant in Ukraine. The explosion was caused by operator error during a safety test which allowed the reactor power to rapidly increase out of control. This caused a fire and the nuclear reactor core was exposed, releasing massive amounts of radiation. Nearby cities had to be evacuated and large areas became uninhabitable for decades due to high radiation levels. The disaster directly caused dozens of deaths and long term effects included many cases of thyroid cancer and other illnesses. Even today, the area around the plant is highly contaminated and will likely remain uninhabitable for over