Six months after the LA County wildfires, researchers found that the actual death toll is likely 15 times higher than official records show. Recovery is underway in the affected areas, including along the Pacific Coast Highway shown above. Photo by Qian Weizhong/VCG via AP

Wildfires

Death Count for 2025 LA County Wildfires Likely Higher than Records Show, BU Research Finds

A new study estimates 440 deaths are attributable to the wildfires that set the area ablaze in January 2025

After devastating wildfires broke out in Southern California earlier this year, burning more than 50,000 acres and destroying nearly 16,000 homes and businesses, official California records reported that the wildfires resulted in 31 direct deaths. But new research indicates that number doesn’t capture the full picture. 

Researchers from Boston University’s School of Public Health and the University of Helsinki found that the actual death toll is nearly 15 times higher. Published in JAMA, the study estimated excess mortality in LA County from January 5 to February 1, 2025, and found that the wildfires contributed to at least 440 deaths during this period. The study is the first to estimate excess mortality associated with these fires, which quickly became one of the worst natural disasters in the state’s history.

“Official death tolls often miss the broader health consequences of disasters like wildfires. With this study, we aimed to deliver a timely, data-driven estimate of the true toll of the LA wildfires—one that includes the hidden impacts of wildfire smoke, disrupted care, and system strain,” says Andrew Stokes, SPH associate professor of global health and senior author of the study. He emphasized the urgency of moving beyond traditional disaster metrics. “We hope these estimates can be used to guide emergency preparedness, protect vulnerable populations, and ensure that policy and resource allocation decisions reflect the full magnitude of harm.” 

The two largest fires, the Palisades Fire in Pacific Palisades and the Eaton Fire in Altadena, ignited on January 7 and spread rapidly before they were fully contained on January 31. At least 179,000 people were forced to quickly evacuate from their homes and many who became stuck in gridlock had to abandon their cars on the road as flames advanced. 

The additional 409 deaths that were excluded from official death records likely resulted from partially attributable factors, such as lung or heart conditions due to air pollution from smoke and burning objects, as well as indirect factors, such as disruptions to critical healthcare, the researchers say. To make these calculations, they used novel excess mortality modeling that they have applied in previous research to assess excess deaths associated with COVID-19. The team then evaluated immediate changes in county-level mortality relative to trends prior to the wildfires. Analyzing weekly all-cause death counts from January 5 to February 1, the researchers observed 6,371 actual deaths in 2025, compared to 5,931 expected deaths, which reflects a 7 percent increase in mortality as the fires swept through the county. 

The team compared these estimates to excess death totals during the same time period in 2018, 2019, and 2024 (excluding 2020–2023, during the height of the COVID-19 pandemic), and performed seven different sensitivity analyses to confirm the strength of their results. 

“Our study demonstrates that wildfires can have large short-term mortality impacts,” says study lead author Eugenio Paglino, postdoctoral researcher at the Helsinki Institute for Demography and Population Health at the University of Helsinki. “Beyond providing precise estimates for the LA wildfires, these findings also support the idea that direct estimates of fatalities, based on cause-of-death coding, should be complemented with indirect estimates, based on statistical methods, to gain a more complete picture of the mortality consequences of wildfires and other natural disasters.” 

The wildfires in January were exacerbated by a perfect storm of factors fueled by worsening climate change, including drought conditions, dry vegetation, low humidity, and high winds in the region that exceeded 90 miles per hour. As forecasters warn of another above-average wildfire season this summer, these findings underscore the need for cities to improve mortality surveillance during and after extreme weather events. 

“As wildfires become more common, it’s important to improve mortality surveillance tools to investigate gaps in climate policy,” says study coauthor Rafeya Raquib, research fellow in the global health department at SPH.

The US and Canada are experiencing an intense fire season, including in Arizona, Utah, and Oregon. Exposure to fine particulate matter and other toxins in wildfire smoke has been linked to a number of health risks and respiratory conditions, including decreased lung function, asthma, and chronic obstructive pulmonary disease (COPD). In the LA County fires, residents were likely also exposed to asbestos, microplastics, and other chemicals from burning vehicles, furniture, and other objects.

“Wildfires, heat waves, and severe storms are increasing in frequency and intensity, threatening the hard-won gains of air quality improvements from effective regulations over the past several decades,” says Gregory Wellenius, professor of environmental health and director of SPH’s Center for Climate and Health, which was not involved with the study. “These extreme events could expose tens of millions of Americans to dangerous levels of air pollution on a recurring basis. This study reminds us that official figures frequently fail to capture the full extent of the harm and loss caused by these disasters.”

The indirect effects from the LA County fires are likely even larger than the results suggest, and the health burdens and outcomes may not be felt equally across affected populations, Stokes adds. Much of the media coverage of the wildfires focused on the destruction of affluent, celebrity-filled neighborhoods, but the fires destroyed communities of all demographics—and the effects from smoke likely reached areas far beyond LA County. 

“Our findings reveal that the true human toll of wildfires far exceeds the visible destruction. The lives lost are not just statistics—they were grandparents, neighbors, workers, and caregivers,” says Stokes. “By uncovering these hidden deaths, so often left uncounted in the wake of disaster, we hope our estimates will inform more equitable, health-focused responses to our growing climate threats.”

A version of this article first appeared in Boston University’s School of Public Health. 

Jessica Colarossi contributed reporting to this article.