In the days since a destructive flood swept through Oʻahu’s North Shore, residents have been asking why they weren’t told to evacuate until their cars were floating barges, until they had to wade and even swim away from their homes. At first, officials’ answers were unsatisfying: Evacuating was a difficult call to make. We didn’t want people driving through flooded roads in the dark. We had already prepared people well. This storm caught us by surprise. But a closer look back raises other