CBC News

· Posted: May 23, 2026 3:06 PM EDT | Last Updated: 26 minutes ago

California's governor declared a state of emergency in Orange County on Saturday as emergency crews continue their efforts to cool down an overheated chemical storage tank and prevent it from exploding.

No injuries were reported after the pressurized tank overheated Thursday and began venting vapours in Garden Grove, according to the Orange County Fire Authority. Evacuation orders were issued for 40,000 people, and several shelters were opened by Friday night, including at three high schools.

California Gov. Gavin Newsom said in his state of emergency announcement that more shelter sites are opening up.

"State agencies are supporting impacted communities to protect public safety, and assist local officials as response efforts continue," Newsom said on social media.

The announcement comes shortly after officials walked back a previous optimistic temperature reading.

Orange County Fire Authority division chief Craig Covey said Friday afternoon that, after hours of emergency crews spraying water to cool it down, the tank and its temperature appeared stable. However, he announced Saturday that was no longer the case.

"Those temperatures we were doing was via drone, doing readings on the [exterior] ... not covering the interior temperatures inside," Covey said in a video update posted on social media.

To ascertain the true internal temperature, Covey said, officials made the call late Friday "to go back offensive."

He said crews originally responded in a defensive posture as a precaution, but now responders are taking part in more risky operations.

"We did put people in harm's way last night," Covey said. Crews made their way to the tank and found the temperature gauge which showed that it rose to 90 F (32 C) on Friday night, up from 77 F (25) that morning.

Covey previously said the main concern is that the tank could fail and crack, releasing the chemical onto the ground, or it could explode.

The tank is located at GKN Aerospace, which makes parts for commercial and military aircraft.

Evacuees carry their belongings as they move to a new location in Garden Grove on Friday. (Ethan Swope/The Associated Press)

The tank holds between 6,000 and 7,000 gallons (22,700 and 26,500 litres) of methyl methacrylate, used to make plastic parts.

If the chemical heats up, it can release a vapour that is harmful to people's health. It can cause respiratory issues, itching and burning eyes, nausea and headaches, said Dr. Regina Chinsio-Kwong, the Orange County health officer.

Crews spray water on an overheated chemical tank at an aerospace plant in Garden Grove, Calif., on Friday. (Ethan Swope/The Associated Press)

"Letting this thing just fail and blow up is unacceptable to us," Covey said Saturday, adding officials are planning contingencies should the worst case scenario occur, such as building dikes and creating sandbag barriers.

"Our goal is ... to not allow that to happen, not let it damage to our community, not let damage our environment."