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
1971 San Fernando earthquake after the Field Act, and damage and cleanup costs there totaled $42,000. Gas lines were broken and separation of the buildings' porches was due to lateral displacement of up to six inches. Following many of California's major earthquakes, lawmakers have acted quickly to develop legislation related to seismic safety. After the M6.4 1933 Long Beach earthquake the Field Act was passed the following month, and after the 1989 Loma Prieta earthquake, the Seismic Hazards Mapping Act and Senate Bill 1953 (hospital safety requirements) were established. Following the San Fernando event, earthquake engineers and seismologists from established scientific organizations, as well