Fires after a major earthquake could destroy 10 times the buildings lost in the Palisades and Eaton fires combined, seismologist Lucy Jones warned LA County supervisors Tuesday, Sept. 29.

Jones, a visiting research associate at the California Institute of Technology who spent 33 years with the U.S. Geological Survey (USGS), delivered the assessment during a Board of Supervisors briefing on earthquake readiness. The county has not experienced a large-scale, damaging earthquake since the magnitude 6.7 Northridge quake killed at least 57 people on Jan. 17, 1994, Spectrum News reported.

"What will happen in our biggest earthquake will overwhelm us, and the best thing we can do is to partner, now," Jones said at the briefing, according to the Daily News.

The briefing grew out of an August motion by Supervisor Kathryn Barger, who cited a University of Hawai'i at Mānoa study published in the Journal of Geophysical Research: Solid Earth. That research found tectonic stress along the San Andreas and San Jacinto fault systems near the Cajon Pass has reached the highest levels in 1,000 years. Barger's motion stressed the findings "are not a prediction that a major earthquake is imminent" but "warrant serious attention."

Kevin McGowan, director of the Los Angeles County Office of Emergency Management, told supervisors the county has updated disaster plans and tested capabilities including helicopter transport and a 24-hour watch center. But he said a major earthquake would test those systems at a scale the county has never experienced.

McGowan added that the county will not have enough first responders for a rapid, countywide response, urging residents to prepare at the family and community level.

The Daily News reported the Office of Emergency Management had just 37 employees before the county added 44 positions after criticism of its response to the January 2025 wildfires. LA County's pre-expansion ratio was one emergency-management staffer for every 256,000 residents. New York City staffs one for every 42,000.

Mark Pestrella, director of county Public Works, told the board he is compiling a report on 1,700 soft-story buildings in unincorporated county areas that are vulnerable to a large quake, the Daily News reported. The Federal Emergency Management Agency (FEMA) ranks LA County's disaster risk index at 100, the highest in the nation.

Barger introduced a second motion calling for a vote Oct. 20 that would direct the county to seek grant funding to expand Community Emergency Response Team (CERT) training and develop an annual full-scale earthquake exercise. The county's 2026–2027 budget includes about $77 million in additional emergency-response funding.

Outside the Hall of Administration at Grand Park, Barger rode a mobile earthquake simulator called the Big Shaker, which replicated a magnitude 7.0 quake. A magnitude 3.6 earthquake had rattled the South Bay near Hermosa Beach on Monday, Sept. 28, with no reported damage.

The county also launched a "Know Your Risk" portal at ready.lacounty.gov/earthquakes, where residents can look up earthquake hazards by address. A multilingual education campaign will run through the Great ShakeOut drill on Thursday, Oct. 15. Residents can register at ShakeOut.org.