Four days before deadly floods swept through western Germany and parts of Belgium last week, Hannah Cloke saw a forecast of extreme rain on a Europe-wide flood alert system to which she belongs. Researchers “were stupidly congratulating ourselves that we were forecasting something so early. … The assumption was that would be really helpful,” says the hydrologist and flood forecaster at the University of Reading. Instead, she was stunned to see scenes of devastation and death despite the ample warnings. “We should not be seeing this number of people dying in 2021 from floods. It just should not be happening.”

As the magnitude of the destruction becomes clear, European scientists are wrestling with how much damage could happen in some of the world’s wealthiest and most technologically advanced countries, despite major investments in flood forecasting and preparation catalyzed by previous inundations. And they are examining whether climate change helped fuel the disaster—and what that might mean for the future.

Beginning on 13 July, intense storms dropped as much as 15 centimeters of rain in 24 hours, swelling streams that then washed away houses and cars and triggered massive landslides. At least 196 people had died as of 20 July—165 in Germany and 31 in Belgium—and the number is expected to rise. On 18 July, German Chancellor Angela Merkel visited the stricken town of Adenau. The scene was “terrifying,” she said. “The German language can barely describe the devastation.” That same day more flash floods struck Bavaria, in southern Germany.