In the late afternoon of October 17, 1989, the northern San Andreas fault ruptured in its first major earthquake since 1906. Centered along the remote Santa Cruz Mountains segment at 5:04 pm, the Loma Prieta M 7.1 earthquake claimed 62 lives, injured nearly 3,800 people, destroyed 963 homes, and damaged over 18,000 others. The combined dollar loss from this quake exceeded $6 billion.

Hardest hit were the communities of Santa Cruz, Los Gatos, and Watsonville. Shaking was very strong in the epicentral area and ground failure, including liquefaction and landslides, played a key role in the destruction. The Interstate 880 viaduct in Oakland collapse, killing 41 people, and the Oakland-San Francisco Bay Bridge sustained a downed segment which restricted travel across the bridge for months.

Non-structural damage, including cracked walls, toppled chimneys, broken windows, and severed water and gas mains, were widespread throughout the Bay Area.

Ominously, no surface ruptures were ever discovered.

There are several sources for information about this earthquake and we shall be upgrading the site during the next few days.

Purchase a poster-sized map of Earthquakes in the United States here.

Track weekly earthquake activity with the comprehensive Seismo-Watch Earthquake Reports.

• Global
• Northern California
• Southern California
• Western Basin and Range

You can also track local activity maps from

• Central California
• Eastern Sierra (Western Basin and Range)
• Mammoth Lakes
• Coachella Valley
• Pacific Northwest

Seismo-Watch EQ Flash! Alert Bulletins are a great way to be informed right away when significant earthquakes occurs.