Loma Prieta Earthquake

On October 17, 1989, an earthquake measuring 7.0 on the Richter scale rocked the San Francisco Bay Area in the early evening, collapsing a portion of the San Francisco Bay Bridge and a three-quarter mile, double-decked section of the Nimitz freeway in Oakland known as the Cypress Viaduct. As well, the shaking damaged a large number of buildings in the cities of Watsonville, Santa Cruz, and Oakland and in the San Francisco districts of the Marina and South of Market. The earthquake resulted in 63 deaths, 13,757 injuries. Property losses amounted to 1,018 homes destroyed, 23,408 homes damaged; 366 businesses destroyed, 3,530 businesses damaged. The total estimated direct economic loss was valued at more than $5.9 billion (US$ 1989 dollars) in public and private property damage. Despite these tragic losses, the Loma Prieta earthquake was a moderate California earthquake whose epicenter was located at a distance over 50 miles south of heavily populated San Francisco and Oakland in the Santa Cruz Mountains on the San Andreas Fault. In less than fifteen seconds of ground shaking, the Loma Prieta earthquake awakened a nation to the threat to life and safety posed by strong, urban earthquakes.

Engineering Aspects of the Loma Prieta Earthquake