A dangerous chemical leak in Orange County that triggered a mass evacuation may be showing the first signs of easing, after firefighters reported spotting what appeared to be a crack in a compromised storage tank — a development that could be reducing internal pressure and lowering the risk of a blast.
Roughly 50,000 residents were ordered to evacuate from the Garden Grove area, southeast of Los Angeles, on Friday when the tank began leaking and fumes drifted across a densely populated region about 8km from Disneyland.
Federal regulators have sent a team of specialists to assist local crews and evaluate potential scenarios. Environmental Protection Agency (EPA) chief Lee Zeldin told CNN yesterday that the “most catastrophic scenario” would involve one tank exploding and triggering a chain reaction among nearby tanks.
“That’s the reason why you see such a big evacuation.”
Still, Mr Zeldin said officials believe “the most likely scenario is one of a low-volume release, where the local authorities are going to be able to monitor, neutralise and contain the threat.”
Firefighters were working “to confirm that the pressure in the tank has been released” and that the danger of an explosion has been eliminated, TJ McGovern, interim fire chief for the Orange County Fire Authority, said in a video post on X.
Around 50,000 residents were forced to evacuate their homes
On Saturday night, crews moved close enough to the tank to collect more information and observed a “potential crack in the tank, which could potentially be relieving some of the pressure in there,” Mr McGovern said.
He described the effort as a crucial step that is helping responders plan next moves with greater confidence. “This operation that we did gave us positive intel to make educated decisions today in the positive light,” he said, noting that experts are now scrutinising the data gathered.
“We’re not there yet, but this was a step in a right direction.”
Officials have not said what caused the leak, which was first reported on Thursday, and Mr McGovern did not address whether the apparent crack is connected to the release.
The tank holds 26,000 litres of methyl methacrylate, a volatile, flammable chemical commonly used in plastic production.
California Governor Gavin Newsom declared a state of emergency for Orange County on Saturday.
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
Fire officials warned on Saturday that the tank’s temperature was rising — a worrying sign that heightened fears of a catastrophic explosion — and crews have been spraying it with water in an effort to keep it cool.
The tank is owned by GKN Aerospace, a UK-headquartered company that operates 32 manufacturing sites across 12 countries, including China, India, Mexico, Turkey, Sweden and Germany, and employs 16,000 people, according to its website.
GKN Aerospace, which develops airplane technology, said in a statement yesterday that it is “working around the clock to mitigate the risk of a leak”.
“We are acutely aware of the uncertainty this incident is causing and sincerely apologise for the ongoing disruption to the local community,” the statement said.
The tank is located around 8km from Disneyland
By yesterday, residents forced out by the evacuation orders still had not been cleared to return, and officials opened additional shelters to take in those displaced.
Disneyland officials said the “resort remains open to guests,” adding that they were monitoring developments closely.
According to the EPA, methyl methacrylate can irritate the skin, eyes and mucous membranes, and may trigger respiratory and neurological effects with acute or prolonged exposure.
Responders were also working to install containment barriers aimed at preventing any spilled chemical from entering storm drains or river channels that ultimately flow into the ocean.
