By LEAH WILLINGHAM and JAMIE STENGLE Associated Press
The risk of a catastrophic explosion at a damaged chemical tank in Southern California has been eliminated following a close overnight inspection that confirmed a crack in the tank relieved pressure and cooled the chemical, authorities said Monday.
The results of the evaluation was “incredibly positive news,” and allowed officials to turn the corner after days of concern about a possible explosion, said Orange County Fire Authority division chief Craig Covey.
However, evacuation orders remained in place for about 50,000 people in Garden Grove, California, located south of Los Angeles. There has been no chemical leak as of early Monday, but the Orange County Fire Authority said the risk to public safety is “ongoing.”
Covey didn’t say in the recorded message what the most likely outcome might be but officials had previously said they hoped to cool off the chemical inside the tank so it wouldn’t leak or explode. The tank’s interior had cooled to 93 degrees F (33.9 degrees C), Covey said, down from 100 degrees (37.7 Celsius) Sunday.
After the tank overheated Thursday and began venting vapors, firefighters have repeatedly sprayed the tank with water in an attempt to cool the chemical inside, methyl methacrylate, which is used to make plastic parts. As the interior temperature rises, methyl methacrylate converts from a liquid to a gas and increases the pressure, according to Purdue University engineering professor Andrew Whelton.
Exposure to methyl methacrylate can cause serious respiratory problems, neurological problems and irritation to the skin, eyes and throat, according to fact sheets about the chemical.
Orange County health officials said the chemical is easy to smell and people may notice it over a large area without being harmed.
Relief among residents after hearing the latest update
Kim Yen, a retiree who has evacuated from her home in Garden Grove, said she’s been following the news on an “hourly basis,” and was pleased to hear in the latest update that there was no longer a risk of an explosion.
“According to that update I am happy and many of us are happy, but still, we are still on our evacuation,” she said.
Yen, who lives just two blocks from the plant, said that while she’s ready to return home, she wants to make sure it’s safe before she does. And, she said, she’s been worried about the emergency crews.
“They are really our heroes,” Yen said.
At a shelter that opened in a hall located in a large park in Fountain Valley, just southwest of Garden Grove, the parking lot was full on Monday as some people sought refuge inside the hall and others set up tents outside. Other people were gathered in the park to enjoy the outdoors on Memorial Day
GKN is a British company that supplies aircraft manufacturers
The tank is at a site owned by GKN Aerospace Transparency Systems, a British company that makes cockpit windows, canopies and windshields for military and commercial aircraft. The tank holds 6,000 to 7,000 gallons (22,700 to 26,500 liters) of methyl methacrylate used to make plastic parts.
GKN Aerospace technical specialists and the Orange County Fire Authority removed external insulation material from the tank to help cool its contents, according to a GKN Aerospace statement released on Monday.
“We apologize for the ongoing disruption this incident is causing and our priority remains its safe resolution, so that residents can return to their homes as quickly as possible,” the statement said.
GKN Aerospace says on its website that it employs about 16,000 people across 32 manufacturing sites in 12 countries and supplies technologies and components used by major commercial and military aircraft manufacturers worldwide.
It remained unknown when the operation would reopen.
GKN Aerospace agreed in 2025 to pay state regulators more than $900,000 to settle violations involving recordkeeping, permitting issues and nitrogen oxide emissions, according to a report on the South Coast Air Quality Management District website.
Manufacture of aircraft components are sensitive to supply chain disruptions
Disruptions at facilities producing specialized aircraft components can be difficult for the global aerospace industry to absorb because supply chains are highly concentrated and already strained, said Richard Aboulafia, managing director of the aerospace consulting firm AeroDynamic Advisory.
Aboulafia said aerospace manufacturing differs from many other industries because aircraft production rates are relatively low, leaving only a small number of suppliers for many specialized parts and systems.
“There’s just not a lot of margin in the system,” he said.
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Stengle reported from Dallas. Associated Press journalist Ethan Swope in Garden Grove, California, contributed to this report.