1989 Loma Prieta earthquake earthquake precursor, more recent studies have cast doubt on the connection, attributing the Corralitos signals to either unrelated magnetic disturbance or, even more simply, to sensor-system malfunction. The earthquake caused severe damage in some very specific locations in the San Francisco Bay Area, most notably on unstable soil in San Francisco and Oakland. Oakland City Hall was evacuated after the earthquake until a US$80M seismic retrofit and hazard abatement work was completed in 1995. Many other communities sustained severe damage throughout the region located in Alameda, San Mateo, Santa Clara, San Benito, Santa Cruz and Monterey counties. Major property damage
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,