The Brief

The giant warehouse that burned for eight days in June in Boyle Heights had used thousands of pounds of anhydrous ammonia to cool the facility.

Anhydrous ammonia is a common refrigerant used in cold storage warehouses. But it is also toxic, and if it leaks, it can cause respiratory irritation; in large doses, it can lead to lung and eye damage and even death. In 2020, a contractor at a Lineage Inc. facility in Statesville, North Carolina, was killed and others were injured during an ammonia release.

On June 17, the first day of the Boyle Heights fire, Los Angeles Fire Department Chief Jaime Moore told CBS LA that ammonia had escaped from the facility.

“We believe an ammonia line was then compromised, because we had a large powerful stream of ammonia coming out,” Moore said as clouds of smoke and flames rose behind him. Moore said the Fire Department had ordered residents to close their windows and doors and shelter in place.

Since then, Lineage and the Fire Department have provided few details to the public about what happened. Lineage has denied that a leak occurred and has said ammonia was removed from its warehouse during the blaze. In July, Moore later reportedly said no ammonia was detected, but the Fire Department has not released results of its monitoring for the chemical or for other toxics during the fire.

More recent ammonia readings raise a separate question: Why is ammonia, which can remain in the air for about a week, being detected more than a month after the fire?

In recent weeks, the South Coast Air Quality Management District has reported levels of the contaminant at a local elementary school about a half a mile from the warehouse that far exceed average exposures for the L.A. area. Lineage has reported even higher levels in fine print on the company’s website. On July 10, for example, one of the company’s readings taken less than 100 feet from peoples’ homes detected ammonia at 13,000 parts per billion, more than double the level the state of California considers safe for short-term exposures. Another reading that also exceeded the safety guideline at 7,000 parts per billion. Several other readings — one measured as recently as Aug. 6 — were also elevated.

Lineage spokesperson Melanie Mendoza didn’t respond to Capital & Main’s request for comment on ammonia levels that the state considers unsafe. She had previously denied in an email that there were any “measurable ammonia concentrations” detected in the community. She later walked that back, saying ammonia levels had not exceeded the state threshold for acute exposures.

“At no point has ammonia reached a level that would pose a health risk,” she said.

What first responders logged

There is still no official report of what happened during the fire. But newly obtained Fire Department records offer a minute-by-minute view from the perspective of first responders as they confronted the blaze in June. A computer-aided dispatch log, obtained by Capital & Main through a public records request, showed that firefighters identified “an active amonia [sic] leak” on the roof of the building at 3:12 p.m. — about 35 minutes after a 911 caller first reported the warehouse fire.

A minute later, the log reports the appearance of “an unknown vapor cloud” rising over the warehouse. Moore later reportedly said the cloud was the result of cold air mixing with hot air and did not contain ammonia.

By 3:25, the log again notes an ammonia leak and says that firefighters would battle the blaze in “defensive mode,” or from outside the structure, likely because it was considered too dangerous to go inside. At the same time, the Fire Department ordered residents to close their windows and doors, shut off air conditioners and shelter in place.

Los Angeles Fire Department hazardous materials crews monitored the air for ammonia and other toxic gases during the fire. But the department has not disclosed its findings. Fire Department spokesperson Branden Silverman told Capital & Main in a statement that “collecting it will take some time.”

A spokesperson for Mayor Karen Bass didn’t respond to Capital & Main’s questions about the facts that caused Moore to change his opinion about the ammonia release or about the department’s delay in reporting the results of its air monitoring during the fire.

Lineage reported a “potential spill” to the California Office of Emergency Services about 90 minutes after the fire erupted, according to a hazardous materials spill report. By law, even potential releases of hazardous materials such as ammonia must be reported to state and federal authorities. The report — provided to Capital & Main by the Office of Emergency Services — paraphrases a Lineage representative, whose name is redacted, as saying: “There is no potential release of anhydrous ammonia and no concerned [sic] of release.”

To date, there has been no publicly released investigation of whether a hazardous ammonia leak occurred.

But on Aug. 4, Los Angeles Public Press reported that the U.S. Environmental Protection Agency demanded that Lineage answer questions about a possible ammonia release. The agency gave Lineage an Aug. 17 deadline to produce a “detailed description and timeline” of what happened, to disclose any contaminants that were released and the calculations made to make that determination. The agency also asked for the results of air monitoring that was conducted when firefighters initially reported an ammonia leak and in the days that followed, as well as any emergency response measures taken to stop or minimize hazards it may have posed.

Mendoza said the EPA inquiry is “the agency’s standard response to the notifications Lineage made in accordance with the law.” She added, “Lineage will continue to provide the EPA with all requested information.”.

Publicly, Mendoza and other company representatives have provided little information and have denied there was an ammonia release.

On Aug. 6, Dominic DiCarlo, Lineage vice president of global safety and compliance, said, “We’re highly confident that ammonia from the refrigeration system was not compromised.”

DiCarlo cited tests the company and local fire officials conducted of the refrigeration system and statements by fire officials.

He also said “no ammonia readings were picked up outside the facility.”

DiCarlo didn’t specify when the readings were taken.

DiCarlo was testifying at a South Coast Air Quality Management District hearing, which was held to resolve odor complaints resulting from the warehouse cleanup. The issue of community exposure to toxic chemicals came up repeatedly during the two-day proceeding. The company agreed to 93 conditions to mitigate odors and reduce residents' exposure to toxics, including additional “fenceline monitoring” at the warehouse site for ammonia and other contaminants and notifying AQMD and the community if readings exceed state or federal thresholds.

Mohan Balagopalan, one of the five-member panel that presided over the hearing, in closing remarks, expressed skepticism about the company’s assertion that there was no ammonia release during the blaze.

“I would take that with a grain of salt,” he said.

Balagopalan, a retired AQMD manager and a toxics expert, said he thought the ammonia hazard was likely one reason firefighters battled the fire from the ground and the air via helicopters instead of remaining on the roof.

Angelo Bellomo, a retired Los Angeles County Department of Public Health deputy director, said an investigation is required to discover whether there was a hazardous materials leak.

He said first responders’ observations can provide important information.

“If they say there is an active anhydrous ammonia release, you don’t have to drill them over that,” he said, adding that ammonia is easily detectable because of its distinctive odor.

Smoke from the warehouse fire inundated Boyle Heights.

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Alejandra Molina

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Boyle Heights Beat

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Concerns about ammonia

A month after the fire erupted, there are renewed concerns about community exposure to ammonia. Ammonia can remain in the atmosphere for a week, according to the federal Agency for Toxic Substances and Disease Registry.

But five weeks after the fire, AQMD air monitoring found ammonia at “much higher than typical levels in the air in urban Los Angeles,” according to Jill Johnston, an associate professor of environmental and occupational health at UC Irvine, who has reviewed the data. The AQMD monitoring was conducted outdoors at Eastman Elementary School, about a half mile from the warehouse.

The Los Angeles Unified School District’s Office of Environmental Health and Safety also found elevated ammonia levels inside a classroom at the school according to an Aug. 10 report, which found elevated levels in a classroom at the Eastman Early Education Center and in one at Humphreys Avenue Elementary School.

Ammonia “can cause wheezing, coughing, irritate the eyes, nose and throat, exacerbate asthma or COPD,” (chronic obstructive pulmonary disorder), Johnston said, adding that “kids in particular tend to be more vulnerable to adverse impacts.”

Boyle Heights residents have told Capital & Main they’ve experienced sore throats, skin rashes, headaches, irritated eyes and worsened asthma, among other symptoms during the fire and its aftermath.

Two of Lineage’s own measurements — conducted by private contractor Onterris — registered ammonia levels that far exceeded safety guidelines.

The state Office of Environmental Health Hazard Assessment advises that ammonia levels at 4,500 ppb or higher can cause adverse health effects during short-term exposures. One of the readings, on La Puerta Street — no more than about 50 feet from homes — was more than double the state standard at 13,000 ppb, while the other registered 7,000 ppb. Several other readings by the company showed elevated levels near Boyle Heights homes as recently as Aug. 6, when ammonia levels reached 3,000 ppb near the warehouse on Prado Street and as far back as July 3, with a 4,000 ppb measurement at the facility fenceline about 50 yards from Indiana Street.

It is not unusual for corporations like Lineage to hire their own environmental testing firms. But Onterris, which until April 2026 was known as the Center for Toxicology and Environmental Health, has earned a reputation for producing health and environmental assessments that favor the companies that hire it. In 2023, when a train derailed in East Palestine, Ohio, and spilled dozens of hazardous chemicals that caught fire, ProPublica and the Guardian reported that CTEH tested residents’ homes with hand-held monitors and told them the air was safe. But independent experts the news organizations consulted said the monitoring devices were insufficient to detect all the chemicals that may have been present and the monitoring period was too short to capture accurate results.

In 2010, two then-U.S. Congressmembers, Rep. Lois Capps, D-Calif., and Rep. Peter Welch, D-Vt., who is now a U.S. senator, cited the company’s track record as they urged Tony Hayward, then-CEO of BP PLC, not to use CTEH to assess the health of cleanup workers in an oil spill in the Gulf of Mexico.

“CTEH has a history of being hired by companies accused of harming public health and releasing findings defending the corporate interests of those that employ them,” they said in a letter.

Onterris’ media representatives did not answer a Capital & Main email inquiring about the company’s environmental track record.

In Boyle Heights, the source of the ammonia detected weeks after the fire broke out isn’t known. The company stored between 10,000 and 24,999 pounds of ammonia in the warehouse daily, according to a report posted by the California Environmental Protection Agency. At the Aug. 6 hearing, DiCarlo said the company had removed all of the ammonia from the facility —more than 10,000 pounds – from the facility.

But Johnston said the elevated levels in the environment could suggest that some ammonia remains in the burnt remnants of the warehouse. Rotting meat that still has not been removed from the structure could also emit ammonia, she said.

What's next

Boyle Heights residents may have an opportunity to question Lineage about whether there was an ammonia leak and how extensive it was. In its letter to Lineage, the U.S. EPA says the company could be required by federal law to hold a public meeting within 90 days of “a reportable accident,” depending on what substances were released. Capital & Main asked Mendoza if such a meeting is planned, but she didn’t respond before this story was posted.

Residents may still face barriers in getting the information Lineage provides in answer to the EPA’s questions. EPA spokesperson Julia Giarmoleo told Capital & Main in an email that “documents are available to the public in response to a FOIA [Freedom of Information Act] request,” which can take weeks or months to be fulfilled.

This article was originally published by Capital & Main. Aaron Cantú contributed to this report. Copyright Capital & Main 2026.

The Los Angeles Unified School District is preparing for possible “Super El Niño” storms that could damage schools and lead to closures, the district announced in a media release Tuesday.

District staff are clearing drains, trimming trees and checking roofs, windows and doors. LAUSD is also testing emergency equipment, including pumps and emergency lighting systems, and stocking supplies such as flashlights and drinking water.

“Preparing for severe weather starts well before the first raindrop,” Superintendent Andrés Chait said in a statement. “We can’t control the weather, but we can take steps now to protect our students and employees and help our schools stay ready.”

The district will monitor weather patterns using information from the National Weather Service and local emergency officials, it said.

LAUSD encouraged families to update their contact information to ensure they receive district calls, texts and emails. Families should also monitor weather alerts, follow emergency officials’ instructions, avoid flooded roads and review safe routes to and from school, according to the release.

“Preparing for a storm is a shared effort — from the crews maintaining school buildings to the principals reviewing emergency plans and the families making sure they can receive critical updates,” LAUSD said in the release. “By taking these steps before the rain begins, Los Angeles Unified is working to help students and employees stay safe and keep school communities as prepared as possible for the winter ahead.”

Southern California is likely in for a solid dose of rain this week, just days after heat and Santa Ana winds helped fuel several wildfires across the region.

Forecasters expect the bulk of the rain to roll into the Los Angeles basin Wednesday night and continue into Thursday morning, with a small chance of thunderstorms and hail.

The San Fernando Valley, San Gabriel Valley and coastal areas across L.A. and Orange counties could get around an inch over the next few days. Hills and mountains could get up to 3 inches.

“We could see some pretty high rain rates,” said National Weather Service meteorologist Mike Wofford. “It's a good storm for this time of year — it's a little stronger than what we would see normally.”

The possibility of significant rain in the mountains raises concerns about flooding in areas recently burned in wildfires, particularly around the Bryson Fire burn scar near Malibu, which is only a few days old. Burn scars can’t absorb heavy rainfall and are susceptible to landslides.

The National Weather Service has issued a flood watch for the Santa Monica Mountains and surrounding communities from Wednesday afternoon through Thursday. That means heavy rain there could flood streets, creeks and rivers. The flood watch area includes both the Bryson Fire and Palisades Fire burn scars.

This will also be the first nontropical storm of the season, meaning it’s moving into the region from the north. Most storms that hit Southern California follow a similar path, especially during the winter, unlike the tropical storms that formed off the coast of Mexico and brought muggy weather to the region this summer.

Nontropical storms also bring cold air to the region. On Wednesday and Thursday, forecasters expect highs in the 60s and 70s. High elevations will be even cooler.

The science research institute that would likely receive $4.2 billion in public taxpayer money if voters approve Proposition 38 this November had only three employees as of last month — far fewer than the 51 staffers it planned to have hired by last year.

Public statements and public records CalMatters obtained raise questions about how well prepared the institute is to shepherd so much money if the bond measure passes.

Prop. 38 would allocate up to $8.4 billion in bonds for scientific research on diseases and cures concerning the immune system, with an emphasis on finding treatments for Alzheimer’s, cancer and heart disease. The ballot language stipulates that a single, unnamed research institute would receive half the bond’s money to conduct research and partner with other researchers if it meets highly specific criteria. Bonds are a type of debt that must be repaid.

Previous reporting by CalMatters found only one institute in California currently meets those criteria: the California Institute for Immunology and Immunotherapy. The institute’s principal funder is billionaire Gary K. Michelson, who wrote Prop. 38 and is by far the largest donor to its political campaign.

Backers of the proposition said state bond money is needed to stabilize research funding after President Donald Trump repeatedly attempted to cut existing and future federal science grants.

The measure’s critics say Prop. 38 is well-intentioned but poorly designed because it overlooks the many established public and nonprofit university and hospital research labs in California. They also say California should not subsidize subsets of scientific research and instead should support research more broadly.

CalMatters obtained documents that included the five-year business plan of the California Institute for Immunology and Immunotherapy. The plan was part of the formal affiliation agreement between UCLA and the institute, which the two parties signed in August 2024. Among other details, the agreement requires the institute to pay UCLA 7.5% of the net revenue of any drugs and technologies developed by the institute’s staff. The institute is one of the founding tenants at a UCLA-owned research park in West Los Angeles, where the institute is leasing 235,000 square feet of research space, the institute says.

Far fewer employees than plan called for

Between summer 2024 and summer 2025, the institute committed to hiring “approximately” 51 employees, including six executives, five “world-class” scientists who can lead research labs, and 40 other employees, such as data scientists, lab technicians, biologists and administrative personnel. Between 2025 and 2027, the institute would hire roughly 90 more workers, including 10 research lab leaders, according to the agreement.

But John Mazziotta, a senior UCLA official who also serves as a board member of the immunology institute, last month said the institute has hired just three employees: a chief operating officer, a general counsel, and a scientific advisor, and “they're well into the search” for a director. Mazziotta, the CEO of UCLA Health and vice chancellor for health sciences at UCLA, made his comments during the Sept. 16 UC Regents meeting.

The Yes on Prop. 38 campaign has repeatedly refused to comment on whether the bond was written specifically for the immunology institute. Claudia Briggs, a spokesperson for the campaign, told CalMatters in July that whichever nonprofit receives the $4.2 billion portion of the bond fund should be a sophisticated one that “is prepared to accelerate lifesaving research immediately while maintaining the highest standards of scientific quality, accountability, and stewardship of public funds.”

At a September press conference, a Yes on Prop. 38 spokesperson appeared to confirm CalMatters’ findings that only one institute currently qualifies to be the one to receive half the bond money. “It is very likely that CIII, which is a research institute affiliated with UCLA, will qualify for half of the funds under the current criteria,” said Robin Swanson. CIII is the initialism for the immunology institute.

According to the five-year plan, the institute was supposed to spend $25 million on personnel between 2024-25 and 2025-26 and $45 million total on operating expenses in that time, including maintenance, utilities and rent. It was also supposed to spend an additional $167 million in that time on capital expenses, such as construction and demolition. However, Mazziotta told UC regents that the institute had so far spent a total of $20 million on “operating expenses, hires” and other expenses.

The Yes on 38 campaign refused CalMatters’ request to interview Michelson for this story, as did Michelson himself in a separate email. A spokesperson for the institute, Becky Warren, sent a written statement that didn't answer CalMatters' questions about employing far fewer people than the five-year plan laid out. Instead, she highlighted the promise of the institute and a few of its milestones, including signing the affiliation agreement with UCLA and clearing a state environmental review of its forthcoming research facility.

The institute won’t get state bond money if it isn’t ready to begin work, “plain and simple,” wrote Swanson, the Yes on 38 spokesperson, in an email. She stressed that though the institute very likely qualifies, the ultimate decision to award half the bond funding is up to the California Department of Public Health.

Institute facility will be built by 2028

The UCLA research park that houses the institute isn’t slated to be fully built until at least late 2028, according to the agenda item of the September UC regents meeting. The research park is a former mall UCLA acquired in late 2023 that’s now undergoing major retrofitting.

But the 2024 affiliation agreement between UCLA and the institute anticipated this. The agreement permitted the institute to use UCLA health research space on another campus property on an interim basis. Mazziotta told regents that research is underway there.

Mazziotta also told the regents the institute's construction costs are not fully funded — it still needs roughly $100 million. He said UCLA was in serious talks with a donor to provide about $50 million to the institute.

If Prop. 38 passes, the bond funding would be provided in increments based on how often the institute requests new money that senior state officials approve. If all the funds are depleted, Californians would repay the bond at a rate of $500 million to $600 million annually for about 20 years.

Institute would be exempt from public records act

CalMatters submitted the public records request to UCLA, which must comply with the California Public Records Act. The institute, as a private nonprofit, does not have to comply. And while Prop. 38 would channel billions of dollars in taxpayer money to the institute, the proposition’s language specifically exempts the nonprofit that will receive the $4.2 billion from state public meetings laws, political reform laws and the public records act. The other half of the funds would go to a council that’ll pick projects led by researchers from a limited pool of universities and nonprofits. The council would generally be governed by the state’s political reform act, which prohibits financial self-dealing.

Briggs defended the institute’s exemption in Prop. 38, writing that applying state transparency laws to existing private organizations would “not fit well with how private entities are organized and operate.” Instead, she noted the selected nonprofit institute would be required to publish annual reports on its research progress and financial plans plus commit to annual state audits, among other disclosures written into the ballot measure.

Still unclear to the UC regents is the relationship between UCLA and the institute on matters of public disclosure. Four senior UCLA officials sit on the institute’s board. So is a document held by those UCLA officials public because it’s related to UCLA affairs or private because it’s related to the institute’s affairs? UC’s general counsel couldn’t explain where that dividing line is after a regent member asked him. The regent member, Michael Cohen, said he wants more clarity when the regents meet again in November.

Gov. Gavin Newsom and the California Democratic Party endorsed Prop. 38, as have dozens of patient and research advocacy groups, plus the state GOP. The union of graduate students and post-doctoral researchers, whose pay often relies on science research funding, has also endorsed the proposition. The union doesn’t represent faculty.

Money raised in support of Prop. 38 now exceeds $66 million, including at least $61.2 million in contributions from Michelson and his policy institute. Roughly $14 million of that includes loans from Michelson. The no camp has raised about $8,800

This article was originally published on CalMatters and was republished under the Creative Commons Attribution-NonCommercial-NoDerivatives license.