Parts of the San Francisco Ferry Building could collapse in an extreme earthquake, as foundation supports fail beneath sections of the building, its south promenade and back waterfront plaza, according to a previously unreported engineering analysis.
The 2024 seismic resilience report also found key structural weaknesses in the building’s 245-foot clock tower that could leave it unstable even in a less extreme quake, posing a risk to the thousands of people who pass through the transit and tourism hub each day.
Commissioned by the Port of San Francisco, which owns the building, the report outlines various possible earthquake scenarios, including a worst-case event statistically expected to occur every 975 years. Such an extreme earthquake, according to a port engineer, would be comparable to a magnitude 8 earthquake on the San Andreas Fault that funnels its energy toward the city, and there’s a 5% chance one could hit the Ferry Building in the next 50 years. But in more common, 100-year events — similar to the magnitude 6.9 Loma Prieta earthquake in 1989 — the structures are not expected to pose any safety risks…