Yolo County blasts watchdog report claiming failure to stop deadly fireworks blast

The Abridged version:

• Yolo County officials rejected a civil grand jury’s conclusions that blamed the county for enabling the conditions at an illegal fireworks facility that exploded last summer, killing seven workers.
• Supervisors approved the formal response at their meeting Tuesday.
• The county attacked the rationale jurors used in their report, and argued the grand jury went beyond what evidence supported.

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Yolo County officials struck a defensive stance in rejecting a watchdog group’s findings that claimed county departments knew about and failed to stop an illegal fireworks operation that exploded last summer, killing seven workers.

Yolo County supervisors on Tuesday approved the formal response to a civil grand jury report released in March that investigated county-level connections to the backyard fireworks facility in the small town of Esparto.

The county response claims jurors reached beyond the evidence available to them at the time when concluding that county officials knew about the illegal fireworks operation for years and failed to act.

The original grand jury report, subtitled “Officials Knew, None Acted,” blamed several county departments for not enforcing building codes or properly inspecting the property for years before the fatal blasts.

What happened?

Seven workers were killed at the site July 1, 2025, in a series of explosions sparked at the fireworks compound on property owned by a Yolo County sheriff’s lieutenant.

The incident led to months of investigation by various agencies and resulted in criminal indictments for eight people connected to the facility and its two fireworks companies. Five of the defendants face murder charges, including the property owner, Samuel Machado.

In refuting the grand jury findings, county officials pointed to the criminal charges against Kenneth Chee, owner of Devastating Pyrotechnics, the main fireworks company based at the Esparto compound, and the other co-defendants.

Public records show that Chee, who is disqualified from holding a federal explosives license because of a felony conviction, obtained a state license through a loophole in California law.

Prosecutors have alleged a conspiracy to run an illegal fireworks ring with connections throughout California, tied to the facility in Esparto.

Filed after the grand jury report, those charges allege that Chee and others illegally ran the fireworks company through fraudulent licenses while deceiving the county about how the buildings and infrastructure at the Esparto property would be used.

The county attacked many of the grand jury findings, arguing that they were reached prematurely and without the extent of public information now available. Jurors filed their report in late March. Arrests were made and criminal indictments were unsealed in April.

Jurors referenced county records in their report, finding a combination of poor communication, limited resources and a culture of looking the other way contributed to the fireworks compound expanding its operations in the lead-up to the explosions.

Despite rejecting many of the grandy jury findings, the county agreed to accept some of the recommendations to improve code enforcement training and workflows while declining some of the others.

Jake Goodrick is Local News Editor at Abridged.