The Loma Prieta earthquake struck the San Francisco Bay Area on 17 October 1989 at 5:04 pm local time. The earthquake lasted about 15 seconds and registered a 6.9 on the moment magnitude scale. The quake killed 63 people, injured 3, 757 and left 8,000 to 12,000 homeless.
The epicenter of the Loma Prieta quake was in the Forest of Nisene Marks State Park in Santa Cruz County, an unpopulated part of the Santa Cruz mountains. The epicenter lay about 2-3 miles (3-5 km) north of Aptos, and unincorporated township, and about 10 miles (16 km) notheast of Santa Cruz. The quake takes its name from Loma Prieta Peak, which lies about 5 m (8 km) to the northeast of the epicenter, in Santa Clara County.
Injuries, Fatalities and Damage Caused
The Loma Prieta quake was responsible for 63 deaths, and a further six deaths were ruled to be indirectly caused by the quake. The quake also caused 3,757 injuries. The highest concentration of fatalities occurred in the collapse of the Cypress Street Viaduct on the Nimitz Freeway (Interstate 880) where a double decker portion of the freeway collapsed, crushing the cars on the lower deck. 42 deaths occurred in this freeway collapse.
In addition, a 50 ft (15 m) section of the San Francisco-Oakland Bay Bridge collapsed; two cars fell to the lower deck and one fatality occurred. The bridge was closed for 31 days, reopening on 18 November 1989.
The earthquake caused damage throughout the Bay Area, in San Francisco, Oakland, Alameda, San Mateo, Santa Clara, San Benito County, Santa Cruz, and Monterey Counties. Property damage as far as 60 m (97 km) from the epicenter occurred due to liquefaction of soil, sand volcanoes, landslides, and ground ruptures. 18, 306 homes and 2, 575 business suffered damage. In Santa Cruz, 40 buildings collapsed and six people were killed.
The Loma Prieta quake was one of the most expensive natural disasters in U.S. History, causing between $6 billion and $13 billion in property damage.