A Hayward magnitude-7.0–7.2 would shake the East Bay’s logistics, refineries and lifelines; contingent business interruption at the Ports of Oakland and Los Angeles–Long Beach, and in tech manufacturing supply chains, is a persistent uncertainty. For reinsurers, the core issue is accumulation: the same footprint can trigger motor, property, DIC, energy, marine, specialty and even cyber business-interruption where data centers and network hubs share utility dependencies.