The Loma Prieta Earthquake of 1989

If you had been walking the Santa Cruz coastline at 5:04 P.M. on October 17, 1989, a powerful earthquake would have jolted you from your revelry with nature. The strong quake, measuring 7.1 on the Richter scale, shook the entire central California coast. It hit during the third game of baseball’s World Series between San Francisco and Oakland, bringing the big earth tremor to a national television audience and the game to a dramatic and sudden end.

The quake was centered northeast of Santa Cruz on the San Andreas Fault near a mountain peak named Loma Prieta (small dark hill). Although not considered the “big one” — the San Francisco Earthquake of 1906, magnitude 8.3, was 16 times more powerful — the Loma Prieta temblor nonetheless killed 62 people, destroyed 367 businesses, and left an estimated 12,000 people homeless when it damaged 18,000 homes, totally destroying 1000 of them. Structural damage and business interruption estimates were as high as $10 billion. Structures alone accounted for $6.8 billion. All that damage happened in a scant 20 seconds. Press coverage centered on the freeway collapse in Oakland that killed 42 people, the destruction in San Francisco, and the collapse of a portion of the San FranciscoOakland Bay Bridge. Although some of the most dramatic damage happened in the Bay Area, the shaking there was less severe than near the epicenter. Much of the Bay Area damage occurred to structures built on filled-in marshland.

The more severe destruction that fell upon the towns of Santa Cruz, Watsonville and other communities near the epicenter was less publicized. The old downtown Santa Cruz, revitalized and turned into the pedestrian friendly Pacific Garden Mall, suffered major damage. A number of unreinforced brick buildings and historic structures collapsed or suffered terminal damage. Today lots still stand empty where businesses once stood, but much of the downtown has been rebuilt. In Watsonville almost 40 percent of pre-1940s frame houses were destroyed or badly damaged. People camped out for weeks in the parks, afraid to return to their damaged homes. Many people felt that the inevitable “big one” had occurred, but that was not the case. Not only was it less severe than the 1906 quake, the Loma Prieta temblor didn’t even relieve the possibility of a major quake happening soon. A study released after Loma Prieta by the U.S. Geological Survey concluded that the possibility of another quake of 7 or greater within 30 years is 67 percent. It also predicts the epicenter will likely be closer to Bay Area populations centers, resulting in a much higher loss.

Disaster preparedness officials are concerned that because most buildings in the Bay Area escaped with no damage, owners have concluded that their structures are earthquake proof. Experts say that if the epicenter of the next quake is near San Francisco, many of these buildings could fail. The potential for major disruption is 10 times greater ($100 billion) than in 1906 because of economic development and a much larger population.