Federal agents searched the GKN Aerospace facility in Garden Grove after a judge approved a warrant to seize records and samples tied to methyl methacrylate, the flammable chemical that overheated and triggered the evacuation of about 50,000 people. The Orange County District Attorney is pursuing a separate criminal probe and has ordered the company not to destroy evidence. GKN says it is cooperating and apologized to the community; health officials reported no detected contamination but will continue extended air and drain monitoring. Several lawsuits have been filed by evacuees.
FBI Searches Garden Grove Aerospace Plant After Overheated Chemical Tank Sparks Mass Evacuation
An overheated chemical tank is sprayed with water to cool it in Garden Grove, California, on 22 May 2026.Photograph: Ethan Swope/AP(Photograph: Ethan Swope/AP)
Federal agents executed a search warrant Wednesday at GKN Aerospace Transparency Systems in Garden Grove, California, after an overheated tank containing methyl methacrylate prompted the evacuation of roughly 50,000 people in late May.
The warrant, signed by a federal judge last week, authorizes seizure of records related to the "storage, use or disposal" of methyl methacrylate and specifically seeks samples from any container suspected of holding the substance. Investigators were also authorized to seize records for cooling systems or other equipment used to control the chemical's temperature.
The Orange County District Attorney's Office is conducting a separate criminal investigation and has ordered the company not to alter or destroy evidence, district attorney spokesperson Kimberly Edds told the Associated Press.
GKN Aerospace Transparency Systems, a U.K.-based unit that manufactures cockpit windows, canopies and windshields, said it is cooperating with investigators. At a community meeting, GKN Senior Vice President Steve Carlin apologized to residents and thanked first responders and local officials for their response.
"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," Carlin said.
Officials say the tank that overheated in late May held an estimated 6,000 to 7,000 gallons of methyl methacrylate, a highly flammable liquid used in plastics and coatings such as Plexiglas and in dental prosthetics. The Environmental Protection Agency warns that exposure can cause respiratory problems, neurological symptoms and irritation of the skin, eyes and throat.
Reports of the overheating surfaced May 21 and evacuations were ordered the next day. Most residents were allowed to return over the Memorial Day weekend after a crack formed in the tank, relieving pressure and averting an explosion. Since the incident, about a dozen residents and local businesses that evacuated have filed lawsuits against GKN, and some people reported strong odors, respiratory irritation, headaches and dizziness.
Orange County health officials say they detected no contamination or fugitive fumes but will continue to monitor air quality for months and inspect sewer and storm drain systems as a precaution.
The Garden Grove incident was the first of two major hazardous chemical emergencies on the U.S. West Coast within a week. Five days later, a tank holding a corrosive chemical at a paper mill in Longview, Washington, ruptured and imploded, killing 11 people.
Federal and local investigations remain active. The Associated Press contributed to this report.
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