In what is being called an “unprecedented” situation, tens of thousands of people in Southern California were told to leave their homes Friday, with officials issuing a dire warning that a chemical tank at an aerospace facility is in “crisis” and will either fail or explode.
Firefighters initially responded to a leak at the GKN Aerospace manufacturing company in Garden Grove on Thursday, for vapor releasing from a 34,000-gallon tank containing methyl methacrylate, which is used in plastic manufacturing, according to the Orange County Fire Authority.
On Friday, the situation in the city, about 30 miles south of Los Angeles, had grown more dire, with officials warning that, though there was no active gas leak or plume, the tank was “actively in crisis” and unable to be secured.
A drone picture shows water being sprayed on a tank as a chemical incident involving a failing tank of flammable liquid called methyl methacrylate, used in the aerospace industry, has forced an evacuation in the surrounding area in Garden Grove, California, U.S. May, 22, 2026.
Caroline Brehman/Reuters
40,000 under evacuation orders
“There are literally two options left remaining: one, the tank fails and spills a total of about 6- to 7,000 gallons of very bad chemicals into the parking lot in that area. Or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around them that have fuel or the chemicals in them as well,” Orange County Fire Authority Division Chief Craig Covey said in a video update Friday.
He added, “We are setting up these evacuations in preparation for these two options — it fails or it blows up,” he said.
A drone photo shows a blocked-off road as a chemical incident involving a failing tank of flammable liquid called methyl methacrylate, used in the aerospace industry, has forced an evacuation in the surrounding area in Garden Grove, California, U.S. May, 22, 2026.
Caroline Brehman/Reuters
Authorities issued evacuation orders for the surrounding area impacting around 40,000 people. Over a dozen schools have temporarily closed, and those adjacent to the evacuation area canceled outdoor activities “out of an abundance of caution,” the Garden Grove Unified School District said.
Authorities initially issued an evacuation order on Thursday that was lifted when vapor conditions improved. However, the evacuation orders were reissued and expanded on Friday due to what police called an “unprecedented” event.
Official: Efforts so far are buying time
An emergency hazmat incident at an aerospace facility in Garden Grove, California, has prompted evacuations in the area, May 22, 2026.
KABC
As of Friday evening, Covey said crews had been able to lower the temperature of the damaged tank — one of three tanks at the facility — with a curtain of water being directed at it. That is “buying us time to continue to sort out: How do we fix this?” Covey said in a video update.
In a follow-up video, Covey said the efforts to keep the tank cool were continuing to work, and that crews were working through the night to figure out how to resolve the situation.
“It is not OK with me just to sit back and watch this thing blow up or fail,” Covey said. “That is not acceptable to me.”
He said another update would be provided Saturday morning.
Officials have said it is unclear when residents will be able to return to their homes.
“This is highly volatile, it’s highly toxic, it’s highly flammable,” Covey said during an earlier press briefing, while urging people to evacuate. “This is not precautionary. This is gonna happen unless some brilliant guy behind me here figures out how we can mitigate this incident. This thing is gonna fail — we don’t know when.”
What is methyl methacrylate?
Methyl methacrylate is an industrial chemical used in plastics and manufacturing and is primarily a respiratory irritant, authorities said. Around 7,000 gallons are estimated to be left in the tank that’s in crisis, Covey said.
Police vehicles block a roadway as a chemical incident involving a failing tank of flammable liquid called methyl methacrylate, used in the aerospace industry, has forced an evacuation in the surrounding area in Garden Grove, California, U.S. May, 22, 2026.
Caroline Brehman/Reuters
Short-term exposure to the chemical can cause skin and eye irritation, as well as breathing problems, according to the EPA.
Orange County Health Officer Regina Chinsio-Kwong said in a video update Friday evening that an explosion could cause the chemical to be released as a vapor, which, if inhaled, could cause “severe respiratory issues.” Other symptoms include a sore throat, runny nose, itchy and burning eyes, and potentially nausea and headache, she said.
GKN Aerospace builds engines and landing gear for both commercial and military aircraft. ABC News has reached out for comment.
California Gov. Gavin Newsom has been briefed on the incident, his office said.
The California Governor’s Office of Emergency Services said it is “closely monitoring the incident in Garden Grove and has deployed personnel to work alongside local partners.”
“Please heed all orders from local authorities — evacuation orders have expanded,” it said Friday.
ABC News’ Sasha Pezenik, Bonnie McLean, Josh Margolin, Jenna Harrison and Jack Moore contributed to this report.
