Since the appearance of railways and canals, industrial revolutions have been characterized by the transformation of physical infrastructure networks as much as by production methods. Now the Fourth Industrial Revolution (4IR) is shaking up the interdependent set of critical physical infrastructure networks on which we all depend, including transport (road, rail, waterways, airports); energy (electricity, heat, fuel supply: gas, liquid and solid); digital communications (fixed, mobile); water (supply, waste water treatment, flood protection); and solid waste (collection, treatment, disposal). This process brings huge opportunities for innovation, but also complex risks.