Quakes: Revealing Another Seismic Danger

Every earthquake reveals a new problem. The Northridge quake exposed one with steel-framed structures. The concern of experts and the city and state with this problem is reassuring.

What good, though, is knowledge that goes unused? I continue waiting to hear word one about the No. 1 quake danger of the Westside: the thousands of pre-Sylmar multistory wood-frame apartment buildings.

The 1971 quake exposed the weaknesses of multistory wood-frame apartments, as then built. The city imposed additional requirements for new construction but did nothing to strengthen existing buildings, as it did for unreinforced masonry structures. The wood-frame apartment problem showed up again in the Marina District of San Francisco. Those units also revealed a special problem of buckling and collapse in buildings with open first-floor garages and carports. In Northridge, the same problem appeared again. Unlike the Marina apartments, in which the first floors contained only parking areas, the Northridge units had both living units and parking spaces on the first floor. When the buildings buckled and collapsed, people, not just cars, were trapped and crushed.

The known seismic faults on this side of the mountain could generate a quake as strong, if not stronger, than the Northridge temblor. Such a quake would be even more deadly because of older, un-retrofitted, multistory, open first-floor, wood-frame apartment buildings here.

After three straight urban quakes demonstrating the danger to life of wood-frame apartments, retrofitting remains a non-issue at City Hall and in Sacramento. How many Westsiders must die next time before our elected representatives realize that un-retrofitted wood-frame apartments, like the masonry units, pose an unacceptable risk of death?

BOB CLARK Jr.

Los Angeles