Europe faced the prospect of a radiation disaster on Thursday when a Russian-occupied nuclear plant was disconnected from Ukraine's power grid, President Volodomyr Zelensky has said. It was only due to back-up electricity kicking in that the Zaporizhzhia plant was able to operate safely, he added. Fires had earlier damaged overhead power lines, cutting the plant off. There is growing concern over fighting near the complex, which is the largest nuclear plant in Europe. "If the diesel generators hadn't turned on, if the automation and our staff of the plant had not reacted after the blackout, then we would already...