1989 Loma Prieta earthquake larger loss of life, as several of the Bay Area's major transportation structures suffered catastrophic failures. The collapse of a section of the double-deck Nimitz Freeway in Oakland was the site of the largest number of casualties for the event, but the collapse of man-made structures and other related accidents contributed to casualties occurring in San Francisco, Los Altos, and Santa Cruz. The history of earthquake investigations in California has been largely focused on the San Andreas Fault System, due to its strong influence in the state as the boundary between the Pacific Plate and the North American Plate; it
1989 Loma Prieta earthquake the earlier shock. Also in Los Gatos, one man died when he exited a building through a window and fell five stories. The Loma Prieta earthquake was named for Loma Prieta Peak in the Santa Cruz Mountains, which lies just to the east of the mainshock epicenter. The duration of the heaviest shaking in the Santa Cruz Mountains was about 15 seconds, but strong ground motion recordings revealed that the duration of shaking was not uniform throughout the affected area (due to different types and thicknesses of soil). At sites with rocky terrain, the duration was shorter and the shaking