FBI seizing evidence at California plant where chemical tank overheated

Ariel view of the chemical tank at GKN Aerospace in Garden Grove, Calif., on Wednesday. William Liang/AP hide caption

LOS ANGELES — 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 because authorities feared a catastrophic explosion.

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. Multiple vehicles and several federal agents were seen outside the facility Wednesday morning.

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.