2014 South Napa earthquake location. At least twelve aftershocks followed, including one of magnitude 3.9. The earthquake was the largest earthquake in the Bay Area since the magnitude 6.9 1989 Loma Prieta earthquake. Governor Jerry Brown declared a state of emergency due to the severe damage and the possibility of aftershocks. President Obama declared a major disaster for Napa and Solano counties. Several older commercial buildings in downtown Napa showed signs of extensive external damage even though many had been retrofitted for earthquake safety protection. The Goodman Library, Napa County Courthouse Plaza, Sam Kee Laundry Building, Downtown U.S. Post Office, Alexandria Hotel and Annex,
1989 Loma Prieta earthquake for the northern San Andreas Fault segment, the San Francisco Peninsula segment, and a portion of that segment which was referred to as the southern Santa Cruz Mountains segment. The thirty year probability for one or more M7 earthquakes in the study area was given as 50%, but because of a lack of information and low confidence, a 30% probability was assigned to the Southern Santa Cruz Mountains segment. Two moderate shocks, referred to as the Lake Elsman earthquakes by the USGS, occurred in the Santa Cruz Mountains region in June 1988 and again in August 1989. Following each event,