The Los Angeles City Council on Wednesday took the most sweeping action on earthquake safety in nearly three decades, instructing building officials to find and catalog apartment buildings vulnerable to collapse in a major temblor.
The survey would focus on wood frame buildings similar to the Northridge Meadows apartment complex, which collapsed and killed 16 people during the 1994 earthquake. A rough estimate by the city put the number of such buildings at about 5,800.
Until now, the city has rejected efforts to launch a citywide survey to figure out which structures might be vulnerable.
“This is something we should’ve done 20 years ago,” said former Councilman Greig Smith, who pushed to revive the issue after he was elected in 2003. “An inventory will allow you to assess what the risks are. And it hasn’t been done.”
The city has not decided what to do once it compiles the list. But seismic experts and policymakers say finding out which buildings are vulnerable is a necessary first step in tackling the problem.
“It's so key,” said L.A. City Councilman Tom LaBonge. “You have to have the data to know how many buildings are like this and where they are. And to give us a kind of road map of what we can do to improve these buildings."
In the 1980s, Los Angeles led the state in seismic safety by locating the city’s roughly 8,000 brick buildings and requiring property owners to retrofit or demolish them. But concerns about costs stalled later efforts to identify and force property owners to retrofit other types of vulnerable buildings that house thousands of residents and office workers across the city.
In response to a motion introduced in July by LaBonge, city building officials developed a plan to winnow out the city’s “soft” story wood-frame buildings built before 1978 with at least two stories and at least five units.
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 soft-story, said Ifa Kashefi, chief of the engineering bureau at the building and safety department.
The city's housing department provided addresses to 29,226 apartment buildings in the city built before 1978, according to Kashefi's report. Staffers would then need to use mapping programs to narrow down which apartment buildings need further field inspection.
The report estimates that 20% of the 29,226 buildings, or about 5,800, will be soft-story buildings, and an additional 11,690 buildings will need to be inspected on site to determine whether they are soft-story buildings or not.
Each inspector would be able to inspect about 30 buildings each day, according to the report, and the overall inventory effort would take about one year and a couple months, a department spokesman said. The report provided a sample checklist of things an inspector would look for in surveying these buildings.
City administrative officials said budgeted resources are available to fund this effort, which would include hiring three people to work for building and safety to create this inventory.
The proposal now goes to Mayor Eric Garcetti for approval.
Garcetti said earlier this year that he supports some type of mandatory retrofitting of older buildings that have a risk of collapse in a major earthquake. He also said he wants buildings across Los Angeles to be graded for their seismic safety
Soft-story wood frame apartments are one of several types of buildings experts say are vulnerable to collapse in a big quake. Another class of buildings that poses particular risks in Los Angeles is older concrete buildings. A Times story in October reported that by the most conservative estimate, as many as 50 of the more than 1,000 older concrete buildings in the city — those built before 1976 — would collapse in a major earthquake, exposing thousands to injury or death.
[Correction at 6:10 p.m.: An earlier version of this story incorrectly reported that the city would hire two people to create this inventory. It's actually three people.]