In Ukraine, the Russian-occupied Zaporizhzhia nuclear power plant was cut off from the national power grid Thursday, after fighting between Russian and Ukrainian forces sparked fires that destroyed a transmission line. Without a source of outside power, the plant’s automated system switched to an emergency backup — a last line of defense against nuclear meltdown. Zaporizhzhia is Europe’s largest nuclear power station, with six reactors and thousands of tons of highly radioactive materials stored on site. On Thursday, Ukrainian President Volodymyr Zelensky said Russia has put the whole world at risk of a major nuclear disaster.

President Volodymyr Zelensky: “Diesel generators were immediately activated to provide energy to the station itself, to support it after the shutdown. The world must understand what a threat this is. If the diesel generators had not turned on, if the automation and our station staff had not reacted after the blackout, then we would have already been forced to overcome the consequences of a radiation accident. Russia has put Ukraine and all Europeans in a situation one step away from a radiation disaster.”