The city of San Francisco stepped up the pressure on property owners who fail to comply with seismic retrofitting regulations this week, posting large red-and-white warning signs on the buildings to make the violations public.
The move comes just weeks after Northern California was rocked by the biggest earthquake to hit the region in a quarter-century, centered close to San Francisco in the state's wine-growing region of Napa County.
The requirement, which could cost property owners up to hundreds of thousands of dollars, affects mostly small apartment buildings and hotels but not single-family homes.