Firefighters dealing with a dangerously overheating industrial tank of a hazardous chemical in California have eliminated the possibility of an explosion after a crack relieved some of the mounting pressure.
Although the worst-case scenario for the tank of highly flammable methyl methacrylate has been ruled out, dangers remain, and tens of thousands of people are still under evacuation orders, the Orange County Fire Authority said.
The tank began overheating on Thursday at the GKN Aerospace facility in Garden Grove, a city of about 172,000 people, roughly 32km south of central Los Angeles.
By Saturday, California Governor Gavin Newsom had declared a state of emergency and evacuation orders were issued for an area home to tens of thousands of people as fears mounted that the tank could rupture and spill up to 7,000 litres of toxic material or explode and endanger nearby tanks.
The tank cooled slightly to 34C from over 38C after the appearance of the crack in the tank over the weekend.
A division chief at the Orange County Fire Authority, Craig Covey, said: "That is incredibly positive news".
Firefighters have been dousing the tank with water to cool it, and have taken the risk of approaching it to check temperatures only after the sun has gone down, officials said.
GKN, a British company, uses its Garden Grove plant to make windows and canopies for commercial and military aircraft, according to its website, and has issued apologies for the disruption its overheating tank has caused to Californians.
Besides the fear of the tank exploding, officials have worried that the toxic chemical could leak, and that vapours expelled from the tank could cause respiratory problems in people after prolonged exposure.
Air-quality monitors had not detected vapour in the latest health update cited by officials over the weekend.
The state's whole-of-government response in #GardenGrove includes real-time environmental monitoring, evacuations, traffic control, shelter operations, and community assistance as crews continue working to protect public safety. https://t.co/XTv6UNJ6jH
— Governor Newsom Press Office (@GovPressOffice) May 25, 2026
GKN has a pattern of regulatory violations at the facility, public records from federal and California agencies show.
According to a settlement document, provided by the South Coast Air Quality Management District, the company agreed to pay the air quality regulator nearly $910,000 (€782,000) in 2024 to settle allegations of multiple rule violations.
In response to a request for comment, a GKN spokesperson declined to elaborate beyond the company's statement about the Garden Grove incident on its website.
