Atropedia Homepage


<!-- @page { margin: 0.79in } P { margin-bottom: 0.08in } -->

The Loma Prieta Earthquake occurred on 17 October 1989 at 5:04 pm. The earthquake lasted about 15 seconds, and registered 6.9 on the moment magnitude scale. 63 people were killed, 3, 757 were injured, and between 8,000 and 12,000 were left homeless. Property losses were estimated at between $6 billion and $13 billion.


Game 3 of the 1989 World Series baseball championship was just starting when the Loma Prieta earthquake hit. Because both of the World Series teams playing that day, the San Francisco Giants and the Oakland Athletics, were based in the affected area, many people left work early to watch the game, or were staying in late that day to participate in after-work parties. As a result, the area’s freeways were experiencing unusually light traffic flows. If traffic had been normal for a weekday rush hour, injuries and deaths could have been much higher; in fact, initial media reports, failing to take into account that day’s unusual traffic patterns, pegged the first death tolls at 300. This toll was corrected in the days following the earthquake.


The largest number of fatalities occurred in the collapse of the Cypress Viaduct on the Nimitz Freeway (Interstate 880). The Cypress Viaduct, a 1.5 m (2 km) stretch of Interstate 880, was constructed in the 1950s, on filled marshland. Little attention was paid to strengthening the Cypress Viaduct in case of a major earthquake, and the freeway remained virtually unchanged from the time of its construction. The combination of outdated earthquake construction standards and unstable ground caused the viaduct to twist, buckle, and then collapse. 41 people were crushed to death instantly. Buck Helm, a 57-year-old dock worker, survived the collapse but died from his injuries less than a month later. The Nimitz Freeway was rebuilt, a process that took eight years; during these years, traffic was detoured through Interstate 980. The freeway was rerouted further west, around West Oakland, where the ground is more stable.



Connected articles