Finding L.A. buildings with quake risk a challenge, official says

Soft story collapse
Crushed vehicles at the Northridge Meadows apartment complex on Jan. 17, 1994, the day of the Northridge earthquake. Sixteen residents were killed in the magnitude 6.7 temblor. (Roland Otero / Los Angeles Times / January 17, 1994)
By Rosanna Xia, LA TIMES
 Los Angeles city building officials have concluded that inspectors would most likely have to visit all of the city’s 29,000 older apartment buildings to determine which ones have a certain type of wood frame that is particularly vulnerable to collapse during a major earthquake.

City staffers are developing a plan to winnow out these so-called “soft” story wood-frame buildings among the 29,000 apartment buildings across the city that were built before 1978, Ifa Kashefi, chief of the engineering bureau at the building and safety department, told a group of structural engineers and stakeholders at the annual Buildings at Risk conference.

Officials have long known about the risk of soft-story buildings, particularly after the Northridge earthquake in 1994, when about 200 of these structures were seriously damaged or destroyed, and 16 people died in the Northridge Meadows apartment complex.

Soft-story structures often are built over carports and held up with slender columns, leaving the upper floors to crash into ground-floor apartments during shaking. No city data exist to easily identify which structures are wood-framed and are soft-story, Kashefi said.

The city’s housing department was able to provide addresses to the 29,000 apartment buildings in the city built before 1978, Kashefi said, and city inspectors would need to go to each address and determine whether a building should be included in this inventory.

A motion, introduced in July by City Councilman Tom LaBonge, asks building officials to present a proposal for how the city would be able to identify wood-frame soft-story residential buildings with at least two stories and at least five units and built before 1978.

“We have a choice. We can either be prepared, or not be prepared,” said LaBonge, who was also on Tuesday’s panel. “It’s about our safety.”

LaBonge’s motion came after San Francisco passed a landmark earthquake safety ordinance this year that requires about 3,000 wooden apartment buildings to be strengthened there. LaBonge said he expected a report from L.A.’s building and safety agency sometime in November.