This Day in History: , Nuclear Disaster br at Chernobyl.br April 26, 1986.br The disaster at Chernobyl, located about 65 miles from Kiev in the former Soviet Union, is the worst nuclear power plant accident to date.br 50 tons of radioactive material was released into the atmosphere after an explosion of the Number 4 reactor, caused by an engineering experiment.br The 30,000 residents of br the nearby community of br Pripyat were evacuated the next day.br The Soviet government br attempted a cover-up.br But two days after the disaster, radiation levels br 800 miles away in Sweden were detected at br 40 higher than the normal level.br 32 people were initially br killed in the Chernobyl plant. br 5,000 Soviets eventually died br from radiation-induced illnesses.br Millions of acres of forest br and farmland across Northern br and Eastern Europe were contaminated.