What is the location of the chemical incident?
As of May 26, 2026, a hazardous chemical incident is ongoing at the GKN Aerospace Transparency Systems facility in Garden Grove, California. The facility is located approximately 35 miles southeast of Los Angeles.
The incident involves a 22-year-old storage tank containing thousands of gallons of methyl methacrylate (MMA), a flammable chemical used in plastics and aerospace manufacturing (1).
The crisis began Thursday, May 21, when the tank overheated and valves became inoperable, triggering a vapor release that prompted initial emergency response.
What is the current containment status of the chemical incident?
The threat of a BLEVE (Boiling Liquid Expanding Vapor Explosion) has been eliminated following an overnight operation on May 25. Throughout the Memorial Day weekend, emergency crews struggled to contain the unstable tank as internal temperatures climbed rapidly, reaching 100°F by Monday.
A confirmed crack in the tank released built-up pressure, and internal temperature decreased to 93°F. Currently, there is no active leak, though officials cite risk of another leak and "very small explosion concern".
Response teams continue cooling operations and have constructed dykes and dams to prevent chemicals from reaching storm drains or the ocean.
Are there any evacuation orders or alerts in place?
A reduced evacuation zone affects approximately 16,000 residents who remain unable to return home. More than half of the original 40,000-50,000 evacuees were allowed to return following Monday evening's announcement after officials averted the worst-case scenario.
The initial evacuation orders issued Thursday affected residents in Garden Grove, Stanton, Anaheim, Cypress, Westminster, and Buena Park. California Governor Gavin Newsom's state of emergency declaration remains in effect, and a presidential emergency declaration was issued Monday (2).
Emergency shelters continue operating for displaced residents.
