The Chernobyl nuclear disaster was the worst nuclear disaster in history - and its effects still reverberate around the world today. A catastrophic eruption ripped through the Ukraine power plant on April 26, 1986, spewing radioactive particles into the sky. The deadly blast was caused by the explosion of RBMK reactor 4, a result of human error and equipment faults. More than 50,000 people from the nearby town of Pripyat were evacuated following the blast.