KYIV, Ukraine — As they struggle to maintain an electricity grid heavily damaged by Russian missiles, officials in the Ukrainian capital, Kyiv, say they have begun planning for a once unthinkable possibility: a complete blackout that would require the evacuation of the city’s approximately three million remaining residents.If it reaches that point, Mr. Tkachuk said, “we will start informing people and requesting them to leave.” For now at least, the situation is manageable, and there were no indications that large numbers of civilians were fleeing Kyiv, he said.But that would change quickly if the services that relied on city power stopped.Across the city, engineers were working to repair the damaged electricity infrastructure, despite having no easy way to obtain the hundreds of millions of dollars’ worth of equipment they would need to fully restore the network.Ukraine’s national electric utility, Ukrenergo, confirmed on Saturday the need to continue rolling blackouts, saying they were necessary to “reduce the load on the networks, ensure sustainable balancing of the power system and avoid repeated accidents after the power grids were damaged by Russian missile and drone attacks.” Updates: Russia-Ukraine War - The soaring number of refugees from the war is increasing disquiet in Europe."