Cal Fire investigator says his warnings about the Esparto fireworks danger were ignored

Why didn’t Cal Fire raid the Esparto facility storing fireworks — which exploded more than year ago, killing seven — after it had done so at a warehouse in Southern California, finding a trove of illegal explosives that belonged to the same company?

A Cal Fire investigator says the agency should have — and he had warned his colleagues in a memo before the Commerce raid that the company, Devastating Fireworks, was “hemorrhaging product onto the streets in several counties including: San Mateo, San Francisco, Santa Clara, Alameda, Yolo, Yuba, and Sacramento.”

The investigator, Gershom Slonim, now calls himself a whistleblower and has come forward to criticize the lack of action taken by the state agency — action that could have saved lives.

“I wish I could have jumped up and down and screamed at my supervisor and my team and said, let’s effing do this,” he said in an emotional interview at The Bee’s office. “I did all I could as one person. I tried my hardest, and it was repeatedly shot down.”

The May 21, 2025, raid on a warehouse in the industrial city of Commerce southeast of downtown Los Angeles seized 500,000 pounds, the largest illegal fireworks seizure in California history. Cal Fire carted away 150,000 pounds the day of the raid. The remaining 350,000 pounds of explosives and raw chemicals stayed in the warehouse because Cal Fire lacked the capacity to remove them safely.

Forty-one days later, the deadly explosion occurred in Esparto

Last week on his LinkedIn profile Slonim posted “The Truth about Esparto Fireworks explosion.” Slonim wrote: “The California Office of the State Fire Marshal (OSFM), specifically senior leadership and Arson and Bomb Investigators Bryan Gougé and Nicholas Schroeder, knew about the illegal operations in Esparto months before the explosion.”

On Monday Slonim received a letter from Cal Fire notifying him that his peace officer status had been suspended. Slonim said he assumed it is because he spoke without authorization.

In response to questions about Slonim’s allegations, Cal Fire spokesperson Ricardo Coronado said in a statement: “CAL FIRE stands by its investigatory and regulatory efforts relating to the Esparto explosion. He also said Cal Fire was aware of Slonim’s LinkedIn post. “The Department cannot otherwise comment on confidential personnel matters,” he said.

“I don’t have regrets, I made a pledge to protect the people of California, not officials at Cal Fire,” Slonim said after being notified he had been suspended.

The warnings and the Commerce raid

Slonim also said in an interview that the Arson and Bomb Unit had information about Devastating Pyrotechnics prior to the July 1, 2025, Esparto explosion for years and did not act on it.

At 3 p.m. on April 30, 2025, Schroeder was notified by agents of the U.S. Department of Transportation’s Office of Inspector General that a warehouse on Tanager Avenue in the City of Commerce was packed with fireworks.

The federal agents, Schroeder wrote in a search warrant affidavit he swore out on May 16, had been surveilling the building under a sealed federal search warrant indicating the address “was possibly involved in illegal activities.”

What the federal transportation investigators were ultimately after has not been made public. The DOT inspector general’s office declined to comment.

In the affidavit, sworn after an initial visit to the warehouse, Schroeder said he believed Kenneth Chee — “the owner of Devastating Pyrotechnics” — was running illegal fireworks sales “outside the scope of his license.”

Chee, and five others, have since been charged with seven counts of murder.

At 9:05 a.m. on May 6, 2025 — 15 days before agents entered the Commerce warehouse — Slonim emailed Gougé, Schroeder and a third investigator a formal workup of Devastating Pyrotechnics with the title “Operation Devastating Consequences.”

“During the ongoing investigation Operation Big Blast in Southern California,” he wrote, “Nick has uncovered a possible link to a Northern California pyrotechnic company.”

Schroeder executed the Commerce search warrant 10 days later. The day after the raid, he dismissed a suggestion that the arson and bomb team raid Esparto, according to Slonim.

In the memo, Slonim wrote that concern about the company dated back years, including a 2017 crash when a Ryder truck spilled fireworks onto a Yolo County road, injuring a truck driver. The company had been hauling them on a motor carrier permit that had been suspended since 2015, according to Slonim’s memo and a California Highway Patrol Accident report obtained by The Bee through a public records request.

Other documents provided by Slonim show the investigation into Devastating Pyrotechnics dated back at least to 2021. In 2024, for example, Deputy Fire Marshal Caleb Phillips contacted Gougé, noting that he had new information related to “the investigation that I was told to stand down on because of an ongoing investigation into Devastating pyro.”

Slonim’s documents show he proposed raiding the Esparto compound — and also was told to stand down because, a colleague texted, federal agents were going to handle it.

Gougé replied the same day to Slonim’s May 6 memo: “I copy… agree with plan to work it up separately. Please move forward with this and let’s see what we can gather. I will get you the original file I worked up on this as well.”

“Hopefully we can do Devastating next month,” Slonim texted Schroeder on May 22, the day after the Commerce raid.

The reply from Schroeder: “Feds are gonna hit it.”

Slonim pressed. “When we looking??”

“No clue yet,” Schroeder responded.

No federal raid occurred.

Other cases

Asked about the possible connection between the Commerce facility and the Esparto compound, State Fire Marshal Daniel Berlant first said in November he didn’t have the answer and then, months later, when it became apparent the two involved Devastating Pyrotechnics, he blamed Johnny Chek, the warehouse leaseholder. He said Chek’s statements were “a lot of finger-pointing” investigators had to “unwind.”

Internal emails, text messages, search warrants, customs records and interviews with more than two dozen current and former state and federal officials show that Cal Fire’s target was Chee’s operation.

Customs records show illegal fireworks kept flowing to Esparto even after the raid: 87,000 pounds arrived on June 26, five days before the explosion.

“That encapsulates the problem and the tragic arc with this,” Slonim said. “There was a pattern of telling people to back off because of an ongoing investigation — an investigation that never resulted in action. “

In his memo, Slonim tied the company to a 2023 explosion at a San Jose storage facility that caused millions of dollars in damage. The roughly 20,000 pounds of fireworks recovered there, Slonim wrote, “were tracked to the same company via EX number.” (An “EX” number is a Department of Transportation identification for an explosive that has been classified for transportation in the U.S.)

Days after the San Jose explosion, a fireworks industry consultant offered Cal Fire help. Dennis Revell, through import data, found that a single Northern California company had brought in the suspect Chinese brand.

Revell emailed Gougé, copying Berlant. “The 6/11/2023 shipment was in excess of 41,000 pounds,” he wrote. Cal Fire did not follow up.

Berlant said in January that Revell’s tip “contained no allegations or sufficient details to initiate an investigation. Nor was there an explicit tie to the San Jose incident.”

Asked for help

Just four arson and bomb investigators work for the state fire marshal, the division that regulates fireworks. The agency has 12,000 working for it. In another exchange, Slonim suggested they “tap prevention,” another Cal Fire unit, for help.

“If we get prevention to always supplement, it doesn’t help our cause,” Schroeder responded.

Gougé, also on the text: “Correct.”

Slonim said he offered to conduct drone surveillance and asked what else he could do to advance an Esparto raid.

“I asked the question: ‘When are we doing this? What information do we need to move forward?” he said. “I was never allowed to move forward with pursuing Esparto without the rest of the team.”

Panic in Los Angeles

After the Esparto explosion, panic spread among Los Angeles officials that another Esparto could happen at the Commerce warehouse, still brimming with fireworks six weeks after the raid. Josh Cook, the U.S. Environmental Protection Agency’s Pacific Southwest administrator, became the point person.

Los Angeles County Supervisor Janice Hahn, whose district includes Commerce, wrote to EPA Administrator Lee Zeldin.

“Our LA County Fire Chief told me about the fireworks in Commerce in the wake of the tragic explosion in Esparto and we agreed it was another disaster waiting to happen,” Hahn said in a statement to The Bee.

Hahn also called Cook during the Commerce seizure.

“This wasn’t a Republican or Democrat issue,” Cook said. “This was a disaster waiting to happen. We needed to move.”

At nearly 11 p.m. on July 23, Cook emailed Los Angeles County Fire Chief Anthony Marrone and the State Fire Marshal’s office: “six (sic) people dying in an explosion in Yolo county, and the City of Commerce situation — in which tons of fireworks remain in the City — we need to act now, and we are.”

Cook enlisted the U.S. Navy. After the evidence was logged, the haul was destroyed at the Naval Air Weapons Station China Lake, in the Mojave Desert. The contraband included tons of what are called overloaded fireworks, along with highly flammable chemicals used to manufacture fireworks.

“What happened in Esparto is a travesty, and the amount of red flags that Cal Fire ignored is frankly unfathomable,” Cook said. “Someone independent should look into what went wrong here.”

‘Esparto broke me’

During the interview, Slonim was accompanied by Daisy, an Australian cattle dog he found on the streets of Sacramento and trained as a service animal. He said she senses his panic attacks — which he has struggled with since Esparto.

His voice cracked when he talked about the Esparto victims and their families and tears were shed.

“I was in the scene for 10 days straight,” he said. “I was working 16-plus hours a day in 100-degree heat, and the smell of the bodies and the family screaming and crying. And I just put my head down to get answers for them the best that I could. Esparto broke me.”

In May, The Bee reported he played a role in blocking Cal-OSHA’s investigators, and family members found him less than sensitive.

He says he was misunderstood.

“It wasn’t that I cared too little,” he said. “I cared too much.”

The tensions with Cal-OSHA, he said, were rooted in genuine concern: “If any statements that they got differed from my body-camera-recorded interviews with witnesses, then the defense could try to say they’re lying.”

He said was under enormous pressure. After the blast, the investigation fell almost entirely on him, he said. California Attorney General Rob Bonta declined a request from the Yolo County’s district attorney to take over, saying he had confidence in Cal Fire.

Slonim cataloged a mountain of evidence alone, coordinated with the ATF and the Yolo DA, and interviewed suspects and grieving families.

“We definitely did not put enough resources into it,” he said. “I tried multiple times to get specialized equipment, more people to conduct interviews, and help processing evidence.” He said he did not receive enough help.

In August, Slonim went on disability leave for PTSD symptoms.

“I fought through my feelings to help get answers,” he said. “And I was definitely rough around the edges, but I always had the victims and families in mind.”

This story was originally published July 17, 2026 at 6:00 AM with the headline "Cal Fire investigator says his warnings about the Esparto fireworks danger were ignored."