"San Francisco's 3,400 Concrete Buildings at Risk of Earthquake Damage"

A list of 3,400 San Francisco buildings that may be at risk of collapse in an earthquake has been compiled by the city, but officials are hesitant to release it due to concerns about causing unease among tenants and investors. The list is preliminary and could change as more information is gathered, but all the buildings were constructed with nonductile concrete before engineers fully understood how much reinforcement was needed to prevent crumbling during shaking. Retrofitting the buildings could cost millions of dollars per structure, and some owners may choose to demolish rather than retrofit. Many of the buildings on the list are associated with vulnerable populations, and retrofitting could displace tenants.