BERLIN—Germany’s national railway operator estimated on Friday that last week’s flooding caused damage worth 1.3 billion euros ($1.5 billion) to its network, offering another glimpse of the extent of the devastation. Authorities are still working to determine the overall cost of the floods that did their worst damage in western Germany and eastern Belgium. German Chancellor Angela Merkel said this week that the damage is “immense” and will take a long time to repair. At least 180 people died in Germany in the flooding and a further 31 deaths were reported in Belgium, taking the overall death toll to 211. German railway operator Deutsche Bahn said that more than 50 bridges, 180 level crossings, nearly 40 signal boxes, over 1,000 electric and signal masts, as well as energy and lighting systems and station elevators were damaged. “Never before has our infrastructure been destroyed to this extent in one go,” said …