Los Angeles County suffered more than $100 million in damage to public property from the barrage of fierce atmospheric river storms that battered the state in early 2023. Costs associated with that damage include debris removal, road and bridge repair and flood damage to buildings – including a sink hole on Iverson Road in Chatsworth that swallowed two cars, with two people escaping uninjured and a mother and daughter being rescued from their vehicle.

It’s frightening to see the damage caused by these storms – but their impact pales in comparison to the type of major earthquake we saw recently in Turkey and Syria, which can cause many, many times more deaths, injuries and destruction in mere seconds.

The Whittier Narrows quake of 1987 brought more than $350 million in damage to the region, destroying more than 100 homes and 1,000 apartment units.

The Northridge quake of 1994 was much worse, bringing about a death toll of 57 and property damage at as much as $50 billion – 143 times more severe than Whittier Narrows. That temblor presented some of history’s most widely publicized images of natural destruction: the flattened Northridge Meadows apartment buildings, collapsed freeway overpasses, grotesquely twisted steel-framed parking structures and crumbling building facades. All total, more than 6,000 commercial and industrial structures including municipal buildings, schools, universities, and medical facilities were damaged, including 11 hospitals. About 39% of all businesses surveyed in the Greater Los Angeles area reported suffering some sort of structural damage because of the quake. About a third of those cases were so severe that buildings were deemed unsafe for occupancy.

But consider this: A 7.5 magnitude earthquake along the Puente Hills fault running through downtown Los Angeles would be five times worse than the Northridge disaster – killing as many as 18,000 people and leaving another 750,000 homeless amid a staggering $250 billion in damages, according to estimates by the U.S. Geological Survey and Southern California Earthquake Center.[i]

It’s this much-warned disaster that prompted the U.S. Geological Survey to rank Los Angeles County No. 1 in the nation for estimated annualized loss, according to HAZUS modeling developed by the Federal Emergency Management Agency.[ii] A recent study at U.C. Berkeley performed by the California Geological Survey supported that finding, ranking potential damage in Southern California higher than that of any other part of the state, including San Francisco.

What makes L.A. the most vulnerable?

One of the main reasons the USGS put L.A. County at the top of annualized earthquake loss has to do with the population density, the types of buildings located here, and the likelihood that they may be damaged when a major quake strikes. Projected earthquake damage is calculated based on population density, the strength or intensity of potential ground shaking and the ability of a structure to withstand it. The California Geological Survey determined that due to the anticipated ground motions, soils and densely populated areas that include thousands of older, vulnerable buildings, our region faces the potential of significant annualized earthquake loss.

Every building is different, and the approaches to safeguarding a structure against earthquake damage remain as diverse as the thousands of soft-story apartment complexes needing retrofits in the Los Angeles area.  Generally speaking, seismologists and structural engineers have identified certain buildings that are more likely to sustain damage in a major earthquake. These include:

  • Soft-story structures, mostly apartment buildings, constructed before 1978: These structures, with parking on the ground floor and units built above, are prone to collapse during major earthquakes.
  • Concrete tilt-up construction built before 1994: Weak connections can fail and cause walls to pull apart from the roof, presenting a collapse hazard.
  • Non-ductile concrete buildings built before 1977: Limited lateral resisting capacity makes these structures brittle.
  • Steel moment frame buildings constructed before 1996: These buildings can sustain brittle fracturing of the steel frames at welded joints between beams and columns.
  • Unreinforced masonry buildings built before 1975: The facades of these buildings can collapse in a quake.

What can we do?

We are at a tipping point. Today, the economics of retrofits and resilience work. The costs of seismic retrofits are relatively affordable, resulting in a high return on investment. The National Institute of Building Sciences found that retrofitting existing residential building stock can produce up to $16 dollars in benefit for every dollar spent. Beyond that, even the simple benefit of eliminating potential earthquake liability judgments can mean the difference between solvency and bankruptcy for building owners and businesses.

There are other strong economic factors to consider when weighing the cost benefits of a seismic retrofit. These include liability and potential loss of income associated with damage, death and injury associated with an earthquake. Loss of income occurs when commercial property is damaged to the point where it is no longer habitable. This can create severe financial hardship for property owners who not only lose their monthly rental income, but are simultaneously facing the costs of recovery while still making monthly mortgage payments.

Seismic retrofits also provide an important value enhancement to buildings. A retrofitted structure is worth more because the projected life of the structure has been extended, based on its ability to withstand a major earthquake. Retrofitted structures also enjoy enhanced market value because they are safer and able to withstand the force of our region’s recurring earthquakes.

Safer buildings also benefit communities. Lives are saved, and injuries prevented. Businesses stay open, housing is secure, people are able to continue going to work, and insurers and lenders suffer fewer losses. Governments maintain tax and other revenues to keep vital public services going when they are needed most, families are protected from job loss and displacement, and social networks remain intact. Serious environmental damage is also avoided with less debris being taken to landfills, and reduced hazardous waste exposure, greenhouse gas emissions and natural resource consumption associated with reconstruction efforts.

Over the past 40 years, structural engineers have developed innovative technologies to reduce building damage and injuries – and studies show that it pays to protect property and retrofit a building against earthquake damage. To learn more about your options, contact Optimum Seismic for a complimentary consultation at 833 978-7664.

Ali Sahabi, a licensed General Engineering Contractor (GEC), is an expert in seismic resilience and sustainability. He is Co-Founder and Chief Operating Officer of Optimum Seismic, Inc., which has completed more than 3,500 seismic retrofitting and adaptive reuse projects for multifamily residential, commercial, and industrial buildings throughout California.


[i] Los Angeles Times,  https://www.latimes.com/socal/glendale-news-press/news/tn-gnp-xpm-2014-03-30-tn-gnp-la-habra-quake-a-reminder-about-dangerous-puente-hills-fault-20140330-story.html

[ii] California Department of Conservation, https://www.conservation.ca.gov/cgs/Pages/Program-SHP/2010-analysis.aspx