Earthquakes Don't Kill People, Buildings Do

Earthquakes Don't Kill People, Buildings Do

Susan Hough and Lucile Jones, U.S. Geological Survey, Pasadena

(San Francisco Chronicle Op-Ed Commentary, 12/4/2002)

Recent small but jarring earthquakes in the East Bay area, centered near San Ramon, provide the latest evidence that this is earthquake country. The recent temblors were generally harmless to everything but nerves and the vast majority of such sequences are not harbingers of imminent large earthquakes. There is however always a small chance, about 6%, that temblors like this will prove to foreshocks. And a recent in-depth investigation by U.S. Geological Survey scientists estimated a 70% probability that at least one magnitude 6.7 or greater quake will strike, somewhere in the San Francisco Bay region, before 2030.

As frightening as this prospect is, it behooves us to remember that earthquakes don't kill people, buildings kill people. The saying is as true today as when it was first coined decades ago, and the earth continues to illustrate the point. A massive magnitude 7.9 earthquake in a sparsely populated part of Alaska recently caused relatively minor damage and few injuries, while much smaller recent earthquakes in Italy and Pakistan claimed dozens of lives.

Californians suffer periodic reminders, such as the 1987 Whittier Narrows earthquake, that even moderate earthquakes can still kill people in California as well. However, we have tended to be confident that our schools are safe. The Field Act, enacted in the aftermath of the 1933 Long Beach earthquake, requires that buildings for elementary and secondary schools and community colleges be built to especially stringent codes. Not only does the Field Act require stronger buildings and approval of all building plans by the State Architect, inspectors check every step of the building process down to ensuring the quality of the concrete and steel. In 1990 the provisions of the Field Act were extended to strengthen requirements for new (although not existing) private schools, although charter schools and day care centers remain exempt. Clearly the recent tragedy south of Rome, which claimed the lives of 26 children, couldn't happen here. Right?

The Field Act has been an important defense against tragedy but it has not solved all our problems. First, although the Field Act standards are strict, they have been improved over time as we have learned more about earthquakes. So older schools, especially those built before we learned the lessons of the 1971 San Fernando earthquake, are built to codes less stringent than now required and could be made stronger.

Recent proposals to solve the space problem facing a number of school districts state-wide propose retrofitting existing retail structures. Yet many experts wonder if these buildings will be as safe as a structure whose construction was monitored from the beginning. Luckily, the State has stepped in and is requiring an expert review of the retrofitting process to evaluate whether it can be done without jeopardizing children's lives. A strict inspection process for retrofitting will be needed.

Even in earthquake-resistant buildings, the fate of the contents of the building is important when the ground starts to shake. In the last few big earthquakes worldwide we have seen people die from toppling bookshelves, flying computers and falling lights. Classrooms are filled with potential weapons, from computers to televisions and paper cutters. In general, they are secured against earthquake shaking only by particularly conscientious teachers or active parent groups. No law or regulation governs school contents.

Building codes also do not apply to existing structures; nor do existing laws provide any direct incentive for retrofitting. Such work is undertaken on single-family homes out of concern for the safety of one's family, yet it is easy to become complacent as memories of the last big local earthquake inevitably fade. For multi-unit housing, the issues are more complex. This is true for not only for low-income housing units, where retrofitting may be prohibitively expensive, but also higher-end condo and apartment units.

For schools, we need to decide as a society how far we will go to protect our children. The Field Act is a great beginning but not the final answer.