Investigation of last year’s deadly Esparto blast continues. What questions remain?

Seven people were killed in a fireworks warehouse explosion last summer and The Sacramento Bee has published more than 30 stories examining the shadowy world of illegal fireworks, lax oversight and missed opportunities which led to the deadly blast.

Here are the latest developments and remaining questions, compiled with the aid of AI, from our award-winning coverage.

The victims, mostly low-wage immigrant workers, were fathers, brothers and sons — people with deep community, church and family ties who were working to support their families. All seven died instantly from “multiple blast and thermal injuries,” the Yolo County coroner said.

No one has been charged in connection with the explosion. Investigators from the Yolo County District Attorney’s Office and Cal Fire’s Office of the State Marshal have continued their investigation, though fireworks-related charges have been filed in Los Angeles and Crescent City.

The Bee received a Northern California Society of Professional Journalists’ James Madison Freedom of Information Award this month for its coverage.

Quick hits, the latest developments

• Costs associated with the explosion in Yolo County have totaled about $1.7 million. The Yolo County Board of Supervisors already was dealing with a $39.6 million budget deficit.
• Multiple sources said a criminal grand jury investigation in Yolo County is examining the fireworks explosion, focusing on whether illegal activity or regulatory failures contributed to the blast.
• Newly released emails show Cal Fire investigators had identified Devastating Pyrotechnics as a target for scrutiny after a 2023 San Jose fire, contradicting earlier claims that there was no clear basis to investigate.
• Emails obtained through public records requests showed that prior to the explosion, Cal Fire fireworks regulators had questioned whether Devastating Pyrotechnics owner Kenneth Chee’s past felony record for a firearms assault should disqualify him from holding a state fireworks license. The agency explained its inaction to The Bee in a statement: “California law only allows the State Fire Marshal to deny a license based on a criminal record for crimes involving explosives or dangerous fireworks or a crime against property involving arson or other fire-related offense.”
• Records confirmed Cal Fire knew the Esparto company dealt in illegal fireworks. Yolo County officials also knew fireworks were stored on site as early as 2022. Less than two months before the Esparto explosion, Cal Fire and federal officials conducted a Southern California raid, finding over 500,000 pounds of illegal fireworks, with the most dangerous fireworks belonging to Devastating Pyrotechnics.
• Cal Fire received emails from Chee’s attorney proposing the company be allowed to move fireworks to Esparto, arguing the company had the means and authorization to move them to a “safe and approved location.” The email also referenced how the Yolo County Sheriff’s Office was aware of the Esparto warehouse and what it was used for.
• Fireworks safety watchdog Lee Miller called for an independent investigation into Cal Fire and the State Fire Marshal’s role in the Esparto explosion, arguing internal reviews lack credibility and public trust.
• The property sites were never inspected by state or federal regulators, and workers were never inspected by Cal-OSHA’s Division of Occupational Safety and Health.
• The explosion site was owned by Yolo County Sheriff’s Lt. Sam Machado and his wife, Tammy Machado, a Sheriff’s Office secretary; adjacent parcels were owned by Tammy’s sister, Reiko Matsumura, a Yolo County Sheriff’s deputy, and included federally approved explosives storage magazines. After the blast, the Machados were placed on administrative leave and Matsumura retired.

Families of victims seek justice

The victims included Jesús Ramos, 18, and his brother Jhony Ramos Jr., 22; Joel “Junior” Melendez, 28; Carlos Rodriguez-Mora, 43; Angel Mathew Voller, 18; Christopher Bocog, 45; and Neil Li, 41, the general manager of the fireworks company.

In the days after the explosion, families — particularly those of the Ramos brothers and their stepbrother, Melendez — said they were left desperate for answers, publicly criticizing what they described as a lack of timely information and compassion from authorities.

Survivors, relatives and Cal-OSHA raised concerns about the conditions under which workers were employed, including allegations that some were paid in cash and received little to no safety training. For days, loved ones waited as the men were listed as missing. Authorities announced on July 5, 2025, that all seven victims had been located.

Actions taken so far

Legal fallout from the Esparto explosion has followed several tracks — civil litigation, government claims and regulatory enforcement amid the ongoing criminal investigation.

Yolo County District Attorney Jeff Reisig and the county’s other elected leaders in July asked Attorney General Rob Bonta to take over the case, citing perceived conflicts of interest and strain on local resources. Bonta declined the request, telling county leaders in a letter: “We have not identified any office-disabling conflict that would require the office to be recused.”

On the civil side, Etta James Farming LLC filed the first lawsuit tied to the blast in July. It sued Devastating Pyrotechnics, BlackStar Fireworks and property owner Sam Machado, among others, in Yolo Superior Court. The farming company alleged the unpermitted fireworks operation was run recklessly and sought damages for losses tied to the explosion and the Oakdale Fire that followed.

On Dec. 23, 2025, several victims’ families filed a $35 million negligence claim against Yolo County, state fireworks regulators and other officials, citing how officials failed to enforce safety laws and allowed the illegal and unsafe operation to continue. Yolo County said a total of 12 claims were filed by victims’ families, along with “a handful” of administrative claims from neighbors whose property was damaged — these claims can precede lawsuits.

Cal-OSHA fined Devastating $221,000 in December for 15 serious violations resulting from the explosion, and Cal Fire permanently revoked the fireworks licenses connected to the companies tied to the property.

Meanwhile, state Sen. Christopher Cabaldon introduced Senate Bill 828, aimed at closing fireworks licensing loopholes and improving communication and coordination between state and local agencies.

Lack of licenses and permits

After being built in 2021-22, the Esparto warehouse operated for three years prior to the explosion without proper licenses, zoning or manufacturing permits for storing commercial‑grade fireworks.

Chee, Devastating Pyrotechnics owner, held a prior felony conviction involving a firearm, which barred him from holding a federal explosives license. However, a loophole in California law allowed him to obtain state fireworks licenses. Volunteer Esparto firefighter Craig Cutright owned BlackStar Fireworks, which operated on the same property. He has long, documented ties to Devastating Pyrotechnics as a show producer.

Experts who viewed footage of the blast questioned whether only standard commercial fireworks were present, suggesting other explosive materials may have been involved. Records show the company imported large quantities of aluminum powder and potassium perchlorate, which are ingredients used to make “flash powder” for high-powered explosives, despite not having a manufacturing license.

Devastating’s attorney Douglas Horngrad and Cutright have both said the two companies are separate. “The claim that Devastating Pyrotechnics and Blackstar ever worked together is false,” Horngrad said. Both Chee and Cutright’s licenses remain suspended and Cutright was placed on administrative leave from the Esparto Fire Protection District.

Closing licensing and regulatory gaps

In the months after the explosion, Cal Fire helped convene a task force — made up largely of local police and fire representatives — that produced a report aimed at tightening California’s fireworks laws.

The report, still in draft form, seeks to close licensing and regulatory gaps and strengthen weak points in a system that relies heavily on small, often underfunded local agencies to verify permits, inspect storage sites and track where dangerous fireworks are actually kept.

Conflicts of interests and warning signs

Records show Cal Fire investigators had reason to scrutinize Devastating Pyrotechnics before the Esparto explosion but did not. Emails following the 2023 San Jose storage-facility fire show investigators were told the fireworks originated with Devastating Pyrotechnics, undercutting later claims that there was no clear basis to focus on the company.

After Esparto, investigators served search warrants linked to Devastating Pyrotechnics, including at a San Francisco home, and later seized illegal fireworks and other explosive materials from an East Los Angeles home. But records and reporting highlight what didn’t happen earlier: Cal Fire did not take steps that might have prompted local scrutiny of the Esparto warehouse, and it repeatedly renewed Devastating Pyrotechnic’s state license without verifying required local permits, which relies on local agencies to issue and enforce them.

The investigation has also intensified scrutiny of potential conflicts of interest. A June 12 email from Sam O’Keefe, an attorney for Devastating, proposed moving about 3,600 cases of seized fireworks from a Southern California warehouse to Esparto, describing it as a “safe and approved location,” and noting the Yolo County Sheriff’s Office knew about the Esparto warehouse and its use.

Records describe ties between the operators and local fire leadership. Esparto Fire Chief Curtis Lawrence said the department conducted “site visits” to familiarize itself with the property but did not conduct formal safety inspections. Emails show he vouched for the operation’s safety to county officials and accepted fireworks shows as “donations” for community events.

Both the Yolo County Sheriff’s Office and the Esparto Fire Protection District later recused themselves, leaving the investigation to Cal Fire’s Office of the State Fire Marshal and other state and federal agencies.

Big questions remaining

Even as investigators have widened their scrutiny of the Esparto blast — serving search warrants, issuing regulatory penalties and examining licensing gaps — many of the most important questions remain unresolved: What set off the fire and series of explosions on July 1, what exactly was stored and handled on the property, and who may ultimately be held responsible?

• What’s still unclear — root cause: Was the trigger a storage failure, a handling mistake, equipment malfunction, and intentional act or illegal manufacturing gone wrong?
• What was on site? Authorities also have not clarified whether anything beyond permitted display fireworks was stored, despite suggestions that more volatile materials were present.
• Local oversight gaps: What happened after a Yolo County building inspector raised concerns about a fireworks company operating there, then allowed the building to be used without further scrutiny?
• Supply chain and customers: Who did Devastating Pyrotechnics and BlackStar sell to? Were illegal fireworks sold to the public as alleged in civil litigation?

Sacramento Local Engagement & Retention Reporter Kat Tran contributed to this story through a proprietary tool powered by artificial intelligence and using our own originally reported, written and published content. Any content produced using AI tools is reviewed by reporters and editors before publication in compliance with McClatchy’s AI policy.

This story was originally published March 25, 2026 at 5:00 AM.