A bridge-building disaster should be incomprehensible in today’s technical world. Humans have been building bridges for centuries. The science should be well sorted out by now — and for the most part, it is. But the National Transportation Safety Board’s investigation of the March 2018 collapse of the FIU pedestrian bridge highlighted basic design flaws and a complete lack of oversight by every single party that had responsibility to either identify the design errors or stop work once it was clear that there was a massive internal failure. We all know “what happened” here. But the “why” is more elusive....