On April 26, 1986, two huge explosions blew apart Unit 4 of the Chernobyl Nuclear Power Plant in the Ukrainian SSR. At least 31 workers and emergency personnel were killed immediately or died from radiation sickness soon after the accident. The nearby village of Pripyat, where most Chernobyl plant workers lived, had to be evacuated and sealed; some 200,000 residents of the area were evacuated. Radioactive debris was carried by clouds over most of northern Europe; long-term effects still being debated, but increased childhood thyroid cancer in Belarus and Ukraine is tied to the accident. This was the worst nuclear accident in history.