FBI searches California aerospace plant after overheated chemical tank incident

Federal agents searched GKN Aerospace Transparency Systems in Garden Grove, California, after a May chemical tank overheating incident that forced roughly 50,000 residents to evacuate.

The June 10 search deepens scrutiny of how the plant handled methyl methacrylate, a highly flammable industrial chemical used in plastics and coatings. According to reporting on the warrant, investigators were looking for documents, records and samples tied to the chemical and to the cooling equipment used to regulate its temperature.

The federal search comes on top of a separate criminal investigation by the Orange County district attorney’s office. GKN said it is cooperating with authorities.

What investigators are looking at

The warrant described in reporting focused on the storage, use or disposal of methyl methacrylate and on the cooling system that was supposed to keep the tank at safe temperatures.

AP reported that the tank held about 6,000 to 7,000 gallons of the chemical. The same report said the tank overheated after a cooling-system valve failed and temperatures rose to about 100 degrees Fahrenheit before stabilizing.

A crack that formed in the tank helped relieve pressure and avert what could have become a catastrophic explosion, allowing most evacuees to return home over the Memorial Day weekend.

The FBI search suggests investigators are now testing whether the emergency resulted from a mechanical failure, a maintenance lapse or a procedural violation, although officials have not publicly identified the cause.

The May evacuation

The overheating incident in late May set off a major public-safety response in the neighborhood around the Garden Grove plant.

As the situation developed, evacuations eventually affected about 50,000 residents. The plant’s location near homes and businesses made the event especially disruptive and renewed questions about hazardous chemical storage in a dense urban area.

Officials later said the tank had stabilized enough for many evacuees to return home over the Memorial Day weekend.

County health officials said no contamination or fumes were released, and they have continued monitoring air, sewer and storm-drain conditions.

Separate criminal probe

The Orange County district attorney’s office is conducting its own criminal investigation into the episode.

A DA spokesperson said the office sent GKN a preservation letter telling the company not to modify or destroy evidence. That step suggests prosecutors want to preserve physical and documentary records while the investigation continues.

GKN said it is cooperating with authorities. The company also apologized to the community at a local meeting, according to reporting cited in the research packet.

Residents and local officials have questioned whether the methyl methacrylate tanks should remain at the Garden Grove site, where the company manufactures cockpit windows, canopies and windshields.

What happens next

Investigators have not said whether they found any violations or whether charges are likely. They also have not disclosed whether the cooling-system failure was mechanical or the result of human error.

Civil lawsuits have already been filed by affected residents and businesses, adding another layer of pressure on the company.

The main open question is whether GKN will change its storage practices or move the chemical tanks away from the neighborhood. For now, the federal search confirms that the May emergency remains an active law-enforcement and public-safety issue.