The City of San Diego has a website (www.sannet.gov/development-services/industry/pdf/urmpn.pdf) that contains a list of 706 local buildings supposedly built out of unreinforced masonry -- that is, bricks held in place with mortar but not tied together by steel reinforcing. On this list, you'll find such prominent structures as the La Jolla Arcade, the venerable complex that lends charm to the intersection of Girard Avenue and Prospect Street. There's the building at 3325 Adams Avenue that once housed a movie theater (and now contains a discount fabric store). In Ocean Beach, Hodad's restaurant and The Black inhabit buildings on this list. Dozens of downtown buildings are listed. Although the Little Pig outwitted the Big Bad Wolf by building his house out of brick, one assumes he didn't live in earthquake country. In seismically active areas, unreinforced masonry is considered one of the most dangerous building materials. Its lethal potential was demonstrated in December of 2003 when a magnitude 6.5 earthquake racked a large section of the Central California coast near San Simeon for four long seconds. Amidst the chaos, two women working in a clothing store in the historic center of Paso Robles tried to make their way outdoors. They died when the second story of the unreinforced masonry building in which they worked slid off the first story and collapsed, crushing them as it fell to the sidewalk.
Don't Stand in the Doorway
If you have the bad luck to find yourself inside an unreinforced masonry building when an earthquake occurs, where's the safest place to be? Not under a doorway, advises Doug Copp.
Copp is the rescue chief and disaster manager of the San Francisco-based American Rescue Team International. He claims to have crawled inside close to 900 collapsed buildings over the past 20 years while working with rescue teams in 60 countries. "Everybody who gets under a doorway when buildings collapse is killed," Copp stated in a recent interview. "How? If you stand under a doorway and the doorjamb falls forward or backward, you'll be crushed by the ceiling. If the doorjamb falls sideways, you'll be cut in half by the doorway. In either case, you'll be dead!"
Based on his rubble-crawling experiences, Copp has concluded that "when buildings collapse, the weight of the ceiling's falling upon the objects or furniture inside crushes these objects, leaving a space or void next to them." Inside such "triangles of life," as Copp calls them, individuals can find shelter. He thus advises, "If you are in bed during the night and an earthquake occurs, simply roll off the bed" and into the safe void surrounding it. If watching television, "Lie down and curl up in the fetal position next to a sofa or large chair." Avoid stairs at all costs, he urges.
Kimberly Shoaf, assistant director of the Center for Public Health and Disasters at UCLA, concurs that doorways are a bad choice for refuge. "A lot of people still think that's what you should do," she says. "When I moved to California, that's what I thought we were supposed to do." This notion arose, she says, "because in old adobe buildings that are not wood-frame buildings, they have a wood-frame doorway. And from the 1933 Long Beach earthquake, there were some significant pictures of old adobe buildings that had fallen and were all collapsed, except for the wood-frame doorway. So that became the norm."
For the last 15 years or so, Shoaf says, schoolchildren in California have been taught another response: namely, to drop, cover, and hold. But she points out that no research has proven "that drop, cover, and hold is the appropriate thing. It makes sense. It's logical. But it's not based on data."
Shoaf says she and some colleagues have surveyed survivors of three fairly recent earthquakes (the 1987 Whittier Narrows quake, the 1989 Loma Prieta quake, and the 1994 Northridge quake), and their findings do suggest that staying put leads to fewer injuries. "The Northridge earthquake is the one for which we have the most data, so it's the easiest to be able to make extrapolations from." The researchers found, "People who stayed in bed were less likely to be injured than those who got out of bed. That was a significant finding. It was the middle of the night. Everyone was disoriented. It was hard for a lot of people to get up, so when they tried, they fell. Falls were a significant injury in that earthquake. Or if they were able to move, they ran into things that had fallen over or moved out of place, or they walked over glass."
The survey data also showed that "men were just as likely or more likely to be injured than women." Also, elderly people were the ones most likely to sustain an injury requiring hospitalization. However, it was the younger adults who had the highest likelihood of being injured. (Shoaf speculates that's "because they do stupid things -- like catching their television sets. They're more likely to take those kinds of actions to protect things.")
Shoaf says her "dream research project" would be to try to validate the drop, cover, and hold strategy using some experimental design. Shake tables, for example, could be used to study "at what level of shaking people can successfully move and at what level it is really detrimental to even try moving." Shoaf says she also would love to use crash dummies to determine "what kinds of positions are the most appropriate to take."
One person who has tried something like this is Marla Petal, director of community mitigation programs for Geohazards International in Palo Alto. Petal extensively studied the deaths and injuries in the Kocaeli, Turkey, earthquake, which killed 20,000 people on August 17, 1999. "We're all trying to put together the mysterious pieces and see how they fit," she says. "Particularly in terms of what to advise people."
"We've shaken buildings to see what happens, but we haven't shaken people," she says. However, Petal and some colleagues who had a shake table did take an informal look at human responses to shaking on one occasion when she was in Turkey. "Our public-education trainers came in one day and saw us shaking stuff on the shake table, and they said, 'Gee, could we try drop, cover, and hold?' 'Cause they were out there teaching that."