1989 Loma Prieta earthquake since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap) until two moderate foreshocks occurred in June 1988 and again in August 1989. Damage was heavy in Santa Cruz County and less so to the south in Monterey County, but effects extended well to the north into the San Francisco Bay Area, both on the San Francisco Peninsula and across the bay in Oakland. No surface faulting occurred, though a large number of other ground failures and landslides were present, especially in the Summit area of the Santa Cruz Mountains. Liquefaction was also a
Interstate 80 in California I-880 was reassigned to SR 17 running from Oakland to San Jose, after two to four years of inactivity. On October 17, 1989, the Loma Prieta earthquake was responsible for 63 deaths and 3,757 injuries. The San Francisco–Oakland Bay Bridge, which is part of I-80, suffered severe damage, as a section of the upper deck on the eastern cantilever side fell onto the deck below. The quake caused the Oakland side of the bridge to shift to the east, and caused the bolts of one section to shear off, sending the section of roadbed crashing down like a trapdoor. Caltrans