A magnitude 6.9 earthquake struck the San Francisco Bay Area during a live World Series broadcast, killing 63 people and causing widespread structural failures.
Key Facts
- Magnitude
- 6.9 Mw
- Deaths
- 63
- Injuries
- 3,757
- Max Mercalli Intensity
- IX (Violent)
- Epicenter
- Forest of Nisene Marks State Park, Santa Cruz County
- Date and Time
- October 17, 1989, 5:04 p.m. PST
By the Numbers
Location
Cause → Event → Consequence
The Loma Prieta segment of the San Andreas Fault System had been largely dormant since the 1906 San Francisco earthquake, earning designation as a seismic gap. Two moderate foreshocks in June 1988 and August 1989 preceded the main rupture, signaling renewed activity along the fault beneath the Santa Cruz Mountains.
On October 17, 1989, at 5:04 p.m. PST, a magnitude 6.9 earthquake ruptured the San Andreas Fault System near Loma Prieta Peak in Santa Cruz County. The shaking reached a maximum Modified Mercalli intensity of IX and caused heavy damage across Santa Cruz County, the San Francisco Peninsula, and the East Bay, including liquefaction in San Francisco's Marina District and widespread landslides.
The earthquake killed 63 people and injured 3,757 others. The collapse of a double-deck section of the Nimitz Freeway in Oakland accounted for the greatest single concentration of casualties. Lighter-than-normal rush-hour traffic—due to the imminent World Series game at Candlestick Park—likely reduced the death toll from the failure of multiple major Bay Area transportation structures.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 63 (earthquake)