California Gov. Gavin Newsom proclaimed a state of emergency in Orange County on Saturday as officials desperately search for a safe resolution to a leaking toxic chemical tank at an aerospace facility.

"The safety of Orange County residents is the top priority," Newsom said. "We are mobilizing every state resource available to support local responders and make sure the community has what they need to stay safe."

According to Orange County Fire Authority Chief Craig Covey, temperatures inside the tank continue to rise, creating a "significantly dangerous" situation spurring more than 44,000 evacuations, officials said.

It was previously believed that the temperatures were cooling inside the Garden Grove industrial tank, estimated to contain 7,000 gallons of methyl methacrylate. However, after crews embarked on a risky operation inside the danger zone, they learned temperatures were increasing at a rate of about one degree per hour. It was at 90 degrees on Friday night after starting the day at 77.

"We did put people in harm's way last night ... with an attempt to go in and neutralize the additional tank," Covey said in a video posted to X on Saturday, explaining that crews entered the zone in an attempt to ensure an additional tank near the leaking tank was stable.

During a news conference on Friday, Covey said the situation was as bad as he'd seen in his 32 years of fire service. In a stunning statement, he said there appeared to be only two potential endings to the saga.

"There are literally two options left remaining: One, the tank fails and spills a total of about [6,000] to 7,000 gallons of very bad chemicals into the parking lot and that area," Covey said. "Or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around it that have fuel or chemicals in them as well."

On Saturday, he said they're evaluating potential third options.

"Letting this thing just fail and blow up is unacceptable to us," Covey said. "Our goal is to find something and not allow that to happen."

He added it'll take "out of the box" thinking and that the OCFA is speaking to experts across the country for help on the issue. It's not yet clear if state or federal authorities will come to Garden Grove to assist with the situation.

Covey also said there are contingency plans ready to be put into place should the toxic and volatile liquid leak out of the tank or if it explodes.

It's unclear how widespread or dangerous an explosion could be, and the timeline remains unknown.

What is methyl methacrylate?

Health experts said that methyl methacrylate — a flammable plastic epoxy that generates its own heat — is a respiratory irritant and potential exposure could lead to lung, skin and eye irritation, nausea and dizziness. The chemical is heavier than air, so its vapor would settle and sink.

Air monitoring is ongoing, and drones are monitoring the temperature of the tank, officials said.

Experts say that the substance has a boiling point less than that of water and contains self-heating properties, which could lead to a "runaway effect."

"In an uncontrolled environment with a leak, you can potentially have a lot in the atmosphere, and any flash or spark or even temperature can cause what is known as a runaway reaction," said USC Assistant Professor of Chemistry Elias Picazo. "Where, when you begin the polymerization, it's exothermic, meaning that the reaction releases heat. ... Heat initiates the reaction, but the reaction releases heat, and so you get what we call 'runaway,' where it's uncontrolled. It can lead to, yes, fires, explosions, where pressure really builds up very quickly."

When did the Garden Grove chemical leak start?

Crews arrived Thursday afternoon at the GKN Aerospace facility in the 12000 block of Western Avenue in Garden Grove after receiving a hazardous materials call just before 3:40 p.m. that day, according to OCFA. 

The chemical in the industrial tank initially stayed at the same temperature, officials said. However, about four hours after firefighters arrived, the temperature rose, causing a relief valve and sprinkler system to activate near the tank.  Firefighters said the sprinkler safety system is designed to cool off the tank if it starts leaking. 

The OCFA said crews initially made progress toward removing the chemical product but determined Friday morning that the "tank that is in the biggest crisis is in fact unable to be secured and mitigated."

The cause of the leak remains under investigation. No injuries have been reported. 

Orange County evacuations

Orange County officials expanded evacuation orders on Friday to homes in a one-mile radius in several cities, including Garden Grove, Cypress, Stanton, Anaheim, Buena Park and Westminster. Evacuation orders were issued for people living in the zone that included: 

• Western border expanded to Valley View St.
• Northern border expanded to Ball Rd.
• Southern border expanded to Trask Ave.
• Eastern border expanded to Dale St.

There was no estimated timetable as to when the evacuation orders would be lifted. 

Evacuation centers are at the following locations:

Garden Grove (Not overnight): Garden Grove Sports & Recreation Center, 13641 Deodara Dr. 

Cypress: Cypress Community Center, 5700 Orange Ave.

Anaheim: Savannah High School, 301 N. Gilbert Street

Fountain Valley: Mountain Square Regional Park-Freedom Hall at 16801 Euclid Street

La Palma: John F. Kennedy High School at 8281 Walker Street

Huntington Beach: Ocean View High School at 17071 Gothard Street

Safety information 

City of Garden Grove 24-hour call center (714) 741- 5444, or visit: ggcity.org/emergency

Orange County public information hotline (714) 628-7085.   

Cancelations and closures

Garden Grove Unified School District officials closed 15 campuses on Friday morning and said they would remain closed until further notice as they continued monitoring the situation.

City officials said that the annual Garden Grove Strawberry Festival would move forward as scheduled, but that the 5k marathon and parade on Saturday were canceled.

Orange County Supervisor Katrina Foley also said that the County of Orange Registrar of Voters had closed the Garden Grove Sports and Recreation Center Vote Center on Saturday as it would instead be operating as a care and shelter site.