1989 Loma Prieta Earthquake
- Date: October 17, 1989, 5:04 PM (PST)
- Casualties: 63
- Magnitude: 7.1
- Epicenter: 37° 2.2' N, 12° 54.49' W
- Fault: San Andreas Fault (?)
- Type: Right-Lateral Strike Slip With Reverse Slip Motion
- Depth: 11 mi
The Loma Prieta Earthquake was the first major quake since the 1906 San Francisco Earthquake along the San Andreas Fault and is infamous for stopping game 3 of the 1989 World Series moments before it was to start. Interestingly, the type of earthquake that occured is not normal for the San Andreas and many believe that it was a offshoot fault. The quake caused part of the San Francisco-Oakland Bay Bridge to collapse as well as the upper level of the Cypress Street Viaduct where most of the casualties (42) occured (It and its heavily damaged sister the Embarcadero Freeway were subsequently demolished).
An underwater landslide and a 4 foot tall tsunami was also triggered by the quake as the sea level near Santa Cruz dropped 3 feet followed 20 minutes later by the tsunami's arrival at Monterey.