THE LOW-PRESSURE region began forming on July 11th over the area where Germany meets Belgium, Luxembourg and the Netherlands. Hundreds of kilometres wide and puffed up by heat—in the Netherlands, it had been the hottest June since 1901—it sucked in moisture from lakes and wet soil all across central Europe. Then it sat there for days, disgorging colossal quantities of rain. Some regions got over 90mm of precipitation on July 13th and a further 70mm or more the next day. Reservoirs filled, sewer systems saturated and streams jumped their banks. Soon entire towns were underwater. Across Germany’s north-western states of North Rhine-Westphalia and Rhineland-Palatinate, bridges, cars and houses were swept away. German headlines called it a