Chernobyl CNN — A Russian drone struck the destroyed nuclear power plant at Chernobyl in an attack overnight into Friday, Ukrainian President Volodymyr Zelensky has said. The strike hit the concrete shelter that covers the plant’s destroyed former fourth power unit, sparking a fire that was later extinguished, he said. The International Atomic Energy Agency (IAEA), the UN’s nuclear watchdog, said that its team at the site heard a large explosion shortly before 2 a.m. local time Friday (7 p.m. ET Thursday).