The 1989 Loma Prieta earthquake in California had a magnitude of 6.9.
The earthquake struck on October 17, 1989, at 5:04 p.m. local time in the Santa Cruz Mountains. It was named after Loma Prieta Peak, near the epicenter, and occurred on a section of the San Andreas Fault system. Although the epicenter was south of the San Francisco Bay Area, the quake caused severe damage across the region.
The event became widely known as the “World Series earthquake” because it interrupted Game 3 of the 1989 World Series between the San Francisco Giants and Oakland Athletics. Shaking collapsed parts of Oakland's Cypress Street Viaduct and damaged structures in Santa Cruz and San Francisco. Soil liquefaction particularly worsened damage in San Francisco's Marina District.
The earthquake killed 63 people and injured more than 3,700. Its maximum Modified Mercalli intensity reached IX, or Violent. The magnitude is sometimes reported differently in historical summaries, but 6.9 is the standard moment-magnitude value used for the mainshock.