As the Astros and Yankees head into Game 4 of the ALCS tonight, we’re reminded of a World Series game that took place out in California between local teams 30 years ago, when an M6.9 earthquake shook Candlestick Park.
On October 17, 1989, thousands of baseball fans had gathered in San Francisco’s Candlestick Park to watch the Oakland A’s and San Francisco Giants play Game 3 of the World Series, or “The Battle of the Bay.” Minutes before the scheduled start of the game, at 5:04 p.m., Pacific Time, as about 35 million television viewers around the world watched, a strong earthquake struck the Bay Area.
No one was injured at the park that evening, and the mostly local fans of the two Bay Area teams, who in customary California fashion pride themselves on remaining unfazed by earthquakes, erupted into cheers and applause. Unbeknownst to them, the situation was quite different elsewhere.
In total, the earthquake was responsible for 63 deaths and more than 3,000 injuries. At least 1,300 commercial and residential buildings were destroyed, and another 20,000 damaged to some degree. More than 16,000 housing units were rendered uninhabitable in 10 Bay Area counties, leaving thousands of people homeless. In addition, transportation links (bridges and freeways in particular), communications systems, and utilities were severely disrupted.
A 50-foot span of the San Francisco-Oakland Bay Bridge collapsed, closing for a month a crucial transportation link between San Francisco and the East Bay. Perhaps most memorably, the upper deck portion of a stretch of Interstate 880 fell onto the lower deck, crushing cars below.
The fault rupture, which extended along a 25-mile segment of the northern San Andreas Fault, originated near the Loma Prieta peak in the Santa Cruz Mountains, some 60 miles south of San Francisco. This disaster is known both as the San Francisco-Oakland earthquake and as the Loma Prieta earthquake, in addition to being known colloquially as the World Series earthquake. It registered a moment magnitude of 6.9 and was felt from as far away as Los Angeles, southern Oregon, and western Nevada.
If the Loma Prieta earthquake were to recur today—with today’s building exposure—AIR estimates it would cause about USD 5 billion in insured loss.
Two earthquakes that struck Southern California only 34 hours and ~7 miles (11 km) apart in the first week of July this year—the M6.4 Searles Valley foreshock and the M7.1 Ridgecrest mainshock—remind us that California earthquake risk is real. Although the insured losses were limited, the Ridgecrest quake was the strongest to strike the State of California in 20 years, since the Hector Mine quake of October 16, 1999. The last earthquake to cause major destruction in the region was 25 years ago, the M6.7 Northridge earthquake of 1994. And just two days ago, on October 15, 2019, a magnitude 4.7 earthquake rattled the San Francisco Bay Area and San Francisco, Oakland, and San Jose experienced weak shaking. Although no one can predict when the Big One will strike, we need to be prepared.