Yolo County disputes grand jury report on deadly Esparto fireworks explosion

Yolo County is disputing a civil grand jury report that found county officials knew about an illegal fireworks operation near Esparto years, and did nothing to stop it before a 2025 explosion killed seven workers. In a 20-page response adopted this week, the county Board of Supervisors said the report blamed staff and elected officials based on speculation and an incomplete record, while agreeing to take up many of its practical recommendations.

The board said the grand jury finished its work before criminal indictments revealed the full scope of the alleged scheme behind the explosion, and that the report assigned blame the evidence does not support.

"The Board will not allow legitimate questions about administrative procedures to be transformed into a claim that County staff or the Board bear causal responsibility for this tragedy," the response reads.

The grand jury report, released in March and titled "Officials Knew, None Acted," concluded that various county officials were aware of illegal fireworks businesses operating at the Esparto site for at least three years. It found that no code enforcement occurred, even though the county had banned fireworks businesses in unincorporated areas since 2001, and that the lack of oversight led directly to "death and destruction."

The July 1, 2025, blast at a property owned by Yolo County Sheriff's Lt. Samuel Machado and his wife, Tammy, killed seven workers employed by Devastating Pyrotechnics. The explosion sparked a 78-acre fire and was felt in Woodland, Davis and Winters, about 20 miles away.

The county's argument

The county's main contention is one of timing. The grand jury finished its report before the Yolo County District Attorney filed criminal charges in April against eight people connected to the fireworks operation. Five are charged with murder.

Those indictments allege a years-long criminal enterprise built on deception — fraudulent federal licensing arrangements, fabricated leases and false statements to officials at every level of government. The county argues that context undercuts the grand jury's finding that staff knew the true nature of the operation and chose to look away.

The county pointed to a June 2022 site visit that the grand jury treated as a missed opportunity for enforcement. County staff were there to inspect a new metal storage building the landowner had represented, under penalty of perjury, would be used only to store farm equipment, the response said. Staff found the building nearly empty. The county said it was the Esparto fire chief who later told building officials the nearby storage containers held "safe and sane" fireworks and functioned as a distribution center.

The county also said it has no authority to license fireworks operations. That power rests with the State Fire Marshal, which the county noted renewed a license for Devastating Pyrotechnics on May 22, 2025 — one day after state investigators seized roughly 500,000 pounds of the company's product, including illegal explosives, in the city of Commerce.

Disputing speculation

The county reserved some of its sharpest language for the grand jury's findings about staff motives. The report had suggested employees may have been reluctant to antagonize sheriff's officials because the property owners worked for the sheriff's office, and that the Board of Supervisors fostered a "culture of tolerance" for code violations.

The county noted the grand jury itself acknowledged it "could not determine definitively" why staff did not pursue the matter further in 2022. "Despite that admission, the Report adopts the most severe possible explanation," the response said. The board said it would not accept findings about the motives of staff or supervisors that "rest on speculation."

What the county accepts

The county did not reject the report wholesale. Across its responses to 16 recommendations, it agreed to implement several. Those include annual ethics training, training on county codes for relevant staff, and better documentation and tracking of code enforcement cases.

Other recommendations, such as creating a county fire warden position and adding code enforcement staff, were marked for further analysis. The county declined a recommendation to use aerial surveys to monitor new construction, citing cost and Fourth Amendment concerns.

The grand jury found the county employs just one full-time code enforcement officer for nearly 1,000 square miles of unincorporated land — a finding the county agreed with.

The criminal case against the eight defendants is ongoing. They are due back in court July 1, the one-year anniversary of the explosion.