FBI seizing evidence at California plant where chemical tank overheated and forced evacuations

Evacuees Rodger Macias, right, and his wife Alendera Marcias set up a tent outside the Elks Lodge in Garden Grove, Calif., on Monday, May 25, 2026. (AP Photo/Ethan Swope)

2026-06-10T17:22:56Z

LOS ANGELES (AP) — Federal authorities served a search warrant on Wednesday at a Southern California aerospace facility where a chemical tank overheated last month, forcing 50,000 residents to evacuate.

The warrant signed by a federal judge last week approved the seizure of documents and records related to the “storage, use, or disposal” of methyl methacrylate, the chemical inside the affected tank.

“Samples of the substance within any tank, tote, drum, vat, vessel, or container suspected of containing or having previously contained methyl methacrylate and/or any hazardous substance” were also sought, according to the warrant.

The warrant also orders agents to seize records related to “any cooling equipment or other equipment used to control or regulate the temperature of methyl methacrylate.”

The FBI confirmed its agents were searching GKN Aerospace Transparency Systems in the Orange County city of Garden Grove.

GKN Aerospace makes cockpit windows, canopies and windshields. The tank that overheated contained 6,000 to 7,000 gallons (22,700 to 26,500 liters) of methyl methacrylate, which is highly flammable. The liquid is used in the manufacturing of plastics and coatings, such as Plexiglas and dental prosthetics.

Exposure to the chemical can cause serious respiratory problems, neurological issues and irritation to the skin, eyes and throat, according to the Environmental Protection Agency.

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Responding to a request for comment on the FBI investigation, a GKN spokesperson told the AP on Wednesday morning: “We are cooperating with authorities at our Garden Grove facility and will continue to do so.”

GKN’s Steve Carlin spoke at a community meeting Tuesday evening. He thanked the firefighters and local leaders who responded to the incident at the plant that employs more than 500 people, and apologized to the community.

“On behalf of GKN and the Garden Grove plant I want to say that I’m sorry that this event and this incident occurred. I understand and I realized sitting here tonight what a disruptive event it was and how unsettling it is to the greater community. Particularly unsettling to us at GKN because of the long history that we have with Garden Grove and how connected we are to this community.”

Carlin said the company would be willing to hold a town hall meeting where residents could ask questions. But he said Tuesday that it is very early in the investigation into what happened, so it is too soon to make decisions about what actions the company might take in response to the incident.

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Separately, the Orange County District Attorney’s Office also is conducting a criminal investigation into the GKN Aerospace plant, according to DA spokesperson Kimberly Edds.

“We have sent a preservation letter to GKN directing them not to modify or destroy any evidence, which the company’s outside counsel confirmed receipt,” Edds told The Associated Press in an email.

About a dozen people and businesses that were among the 50,000 evacuated during the chemical emergency have filed federal lawsuits against the company.

County health officials assured residents that no contamination or fumes were released, and that they would keep monitoring the air for several months and checking the sewer and storm drains.

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Associated Press journalists Martha Bellisle in Seattle and Josh Funk in Omaha, Nebraska, contributed.

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