California Gov. Gavin Newsom declared a state of emergency in Orange County on Saturday as crews worked to cool an overheated chemical storage tank at an aerospace facility in Garden Grove. The declaration followed evacuation orders affecting about 40,000 residents, with shelters opened at several locations, including three high schools.
The incident began Thursday when a pressurized tank at GKN Aerospace overheated and started venting vapours, according to the Orange County Fire Authority. No injuries have been reported. The tank contains an estimated 6,000 to 7,000 gallons of methyl methacrylate, a chemical used in producing plastic parts. Health officials said vapours from the chemical can cause respiratory irritation, burning or itching eyes, nausea and headaches.
Emergency crews had initially taken a defensive approach, spraying water on the tank from a distance while monitoring its temperature by drone. On Friday, officials said the situation appeared stable. However, Fire Authority division chief Craig Covey later said those readings reflected only the exterior of the tank, not its internal temperature.
Crews shifted to more direct operations late Friday to obtain internal readings. Covey said responders reached the tank and found a gauge showing the temperature had risen to 90 F, or 32 C, up from 77 F, or 25 C, earlier that day. Officials have said the principal risks are that the tank could crack and release chemicals onto the ground, or explode.
Newsom said state agencies were assisting local officials and supporting public safety efforts. Additional shelter sites were being opened as the response continued.
Authorities said they are preparing contingency measures, including dikes and sandbag barriers, in case the tank fails. Officials said their priority is to prevent harm to residents and limit environmental damage while crews continue cooling operations. The emergency order allows broader state coordination and resources during the incident.