On April 17, 1906, San Francisco was the financial hub of the West and the eighth largest city in the country. At 5:12 a.m. on April 18, a massive earthquake turned parts of the city into rubble — and what the quake didn’t get, fires created by broken gas mains did. More than 30,000 people lost their lives; 225,000 of the city’s 400,000 citizens were left homeless.
But that’s the past. Many San Franciscans next week will be commemorating the centennial of their city’s worst day while worrying that one even harsher is yet to come. It sounds like an urban legend, but there apparently was a FEMA emergency training session in August 2001, during which participants agreed on the three major disasters most likely to strike the United States: a New York terrorist attack, a massive hurricane hitting New Orleans and a major California earthquake.
Two of the three, of course, have occurred, and the third will come — but it probably is not imminent. An article in the Proceedings of the National Academy of Sciences last year noted that although the San Francisco area will almost surely be struck by a Richter 7.0 or greater earthquake sometime during this century, the likelihood in the next 20 years is only 25 percent. (A Richter 7.0 yields as much energy as the largest thermonuclear weapon ever made.)
The common nightmare scenario has that enormous bomb going off in the San Andreas Fault that runs beneath San Francisco. But another vision of horror has the epicenter of the quake in Oakland or Berkeley — 1 million people live over the Hayward Fault, which runs right underneath the University of California football stadium. Still, that’s unlikely: The U.S. Geological Survey pegged the severe Hayward Fault possibility at only 8.5 percent during the next 30 years.
Those percentages are important because they influence the action of both politicians and homeowners. An East Bay politician who considers the Hayward Fault odds and plays Russian Roulette throughout the length of his career is holding two six-shooters with a bullet in only one of the cylinders. The likelihood of escaping disaster during a particular four-year term of office is high.
The same odds lead many Californians to go without earthquake insurance. Premiums run $1,000 to $2,000 per year, and only 15 percent of California homeowners carry it. A big San Francisco-area earthquake would probably leave 360,000 people homeless, according to the Association of Bay Area Governments. That figure could be cut substantially if homeowners bolted their houses to their foundations, but few do.
Californians are also gambling with the levees of the Sacramento-San Joaquin Delta, a 1,600-square-mile plain that is up to 30 feet below sea level. An earthquake-caused collapse could turn the area, with its thousands of homes, into a lake. Brackish water rushing in after levee failure would contaminate the drinking water for 22 million Californians and the irrigation supply for 5 million acres of the Central Valley, America’s leading agricultural producer.
Southern California’s water supply could be protected by building a canal to bring water from the Sacramento River to the southern part of the state without having to send it through the readily flooded Delta, but Californians have refused to build one. They also have been slow to improve thousands of brick and concrete school buildings constructed before a 1978 state building code upgrade, even though one official report noted that 78 percent of such buildings were "not expected to perform well in future earthquakes."
There, also, politicians can play the percentages: Say that children are in school seven hours per day over 180 days of the year. If a huge earthquake occurs and buildings collapse, there’s only a one in seven chance that children will be buried in the rubble. Gambling with lives in that way seems foolhardy at the least, but many people have short memories and even shorter perspectives on events yet unseen.