A team of scientists has declined to give the city a list of older concrete buildings that may collapse during a major earthquake, the mayor’s office said.
Los Angeles city officials said this week that they requested the data from the researchers, who, as the Los Angeles Times reported Sunday, identified about 1,500 potentially vulnerable concrete buildings in L.A. through public records and a walking survey. Advocates said the list would give the city a head start in tackling the concrete-building problem.
“At our direction, an official from the Department of Building and Safety did call the researchers, and they declined to provide the list,” said Jeff Millman, spokesman for Mayor Eric Garcetti.
The researchers are led by UC Berkeley engineering professor Jack Moehle and backed by a $3.6-million grant from the National Science Foundation. They did not respond to calls and emails from The Times.
More than 1,000 old concrete buildings in the city may be at risk of collapsing in a major quake, according to a Times analysis. Experts say sorting out which present the greatest danger of injury and death to occupants is a daunting problem that would require building-by-building assessments by structural engineers.
Concrete buildings may look strong, but many older structures are vulnerable to the sideways movement of a major earthquake because they don’t have enough steel reinforcement to hold columns in place.
Los Angeles officials have known about the dangers for more than 40 years but have not forced owners to make their properties safer. Despite repeated recommendations to compile a list of concrete buildings that require additional scrutiny, city officials have not done so, The Times reported.
One of the most immediate seismic safety questions Garcetti faced this week was whether to ask Moehle’s team for its list of older concrete buildings.
Moehle previously declined to give the list to The Times, saying his team could be exposed to legal liability from building owners because the data are far from definitive. The list was designed to be a first step. Each building would have to be examined more thoroughly to determine whether it needed strengthening.
“I don’t want to get sued. It’s that simple,” Moehle said to the Times. He later added in an email: “If the city wanted the data we probably would give it to them.… It would be their responsibility to figure out what to do with it.”
Two City Council members, Tom LaBonge and Bernard Parks, introduced motions this week to request more study on the city’s older concrete buildings.
LaBonge’s motion asks for the city’s Department of Building and Safety to take the “first step” and report on possible ways to conduct “a comprehensive survey of non-ductile concrete buildings (built prior to 1976) in Los Angeles which have not been seismically retrofitted, including recommendations for methods of retrofitting and related costs."
In a separate proposal, Parks asked the Board of Public Works to collaborate with the city attorney to gather data on older concrete buildings that need retrofitting and “identify via city records the accuracy of such data." His motion asks that the report include recommendations and ordinances to address safety and liability issues.
Garcetti said Thursday that he was thinking about having a “chief resilience officer” to oversee preparations for a major earthquake and ensure Los Angeles can minimize the disaster’s damage.
Garcetti’s suggestion for a top coordinator of earthquake issues came as he prepares to announce what he called “some very concrete steps” to enhance seismic safety in a city with a long history of deadly temblors.
“The problem is there are lots of different pieces of this, but there’s nobody at City Hall who ultimately is kind of the earthquake expert, so I’m looking at that,” Garcetti said.