Emergency responders have issued an urgent alert over a chemical leak from a tank at an aerospace facility in Garden Grove, Orange County, prompting evacuation orders affecting roughly 40,000 residents and leading to school closures.
Officials have described the incident as a ‘crisis situation’, warning the overheated tank could suffer a catastrophic failure.
Authorities say the vessel contains methyl methacrylate, a toxic chemical, and they are concerned it could either begin leaking in a major way or explode.
Methyl methacrylate (MMA) is commonly used in the production of plastics, but exposure can pose health risks including respiratory problems, according to the Environmental Protection Agency.
The emergency began on Thursday (May 21) when the tank started venting vapors. Responders also observed what appeared to be bulging, a sign the container may be dangerously overheated and at risk of rupturing.
The Orange County Fire Authority (OCFA) said that while a spill would be difficult to manage, it would be preferable to an explosion, which could cause significantly greater destruction.
Crews have been dousing the tank with water in an effort to cool it down and have placed sand barriers to help contain any potential release.
Even with evacuation instructions in place, Garden Grove police said about 15 percent of residents have declined to leave when asked.
The facility is located approximately five miles from Disneyland.
***Incident Update***
Incident Commander Chief Covey provides an update on the hazardous materials incident in Garden Grove. Our next update will be provided tomorrow morning unless there is a change in incident status. pic.twitter.com/z8xns32iyS
— OCFA (@OCFireAuthority) May 23, 2026
OCFA Division Chief Craig Covey said there are ‘literally two options left remaining’.
Speaking to reporters, he said: “One, the tank fails and spills a total of about 6,000 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.”
Update on evacuation centers:
Garden Grove Sports and Recreation Center
13641 Deodara Dr.
Garden Grove, CA 92844Cypress Recreation and Community Center
5700 Orange Ave.
Cypress, CA 90630— OCFA (@OCFireAuthority) May 22, 2026
Officials added that air quality checks are ongoing and, as of the latest update, readings have remained within healthy limits.
The evacuation area spans north of Trask Avenue, south of Ball Road, east of Valley View Street, and west of Dale Street. Reception centers have been set up at the Garden Grove Sports and Recreation Center and the Cypress Recreation and Community Center.
Gov. Gavin Newsom’s office said in a statement: “Our office continues to closely monitor the situation, and we urge residents in impacted areas to follow guidance from emergency officials.”