Orange County chemical leak leaves 50,000 Californians still evacuated

More than 50,000 people remained evacuated after a chemical leak at GKN Aerospace Transparency Systems Inc. in Garden Grove turned a neighborhood-sized industrial problem into a regional public-safety emergency. The leak began Thursday, May 21, at the facility at 12122 Western Avenue, where a 34,000-gallon storage tank containing methyl methacrylate overheated and started leaking.

Officials described methyl methacrylate as a volatile, highly flammable liquid used to make acrylic plastics, and the evacuation footprint quickly spread across a wide swath of north Orange County. The zone included areas north of Trask Avenue, south of Ball Road, east of Valley View Street and west of Dale Street, with smaller sections of West Anaheim, Cypress, Buena Park and Stanton also covered. Firefighters first arrived around 3:30 p.m. Thursday. Authorities initially evacuated about 50,000 residents, briefly lifted the order Thursday evening, then reissued it Friday morning as conditions worsened.

By Sunday, the incident had entered its fourth day, with roughly 50,000 people still under evacuation orders and schools in Garden Grove, Magnolia, Savanna, Westminster and Cypress closed until further notice. Local authorities also set up a public information hotline and call center as families waited for a return timeline that still depended on the tank itself.

Fire officials said the tank’s internal temperature had climbed above 100 degrees, far above the preferred range for the chemical. Crews warned that the tank could fail in one of two ways: it could spill thousands of gallons of toxic material, or it could explode. Orange County Fire Authority officials said the worst-case outcome was a BLEVE, or Boiling Liquid Expanding Vapor Explosion. On Saturday night, crews found cracks in the tank, later describing multiple cracks, and aerial footage showed firefighters chiseling and hammering at the exterior while removing part of it for testing.

An all-night operation was planned to test the tank’s pressure and determine whether the crack was easing the danger or whether vapor was still building inside. OCFA interim chief TJ McGovern said the overnight work was meant to confirm whether the BLEVE threat had been eliminated, with a morning update expected to determine whether the evacuation zone could be reduced.

The response quickly reached beyond local fire lines. Gov. Gavin Newsom declared a state of emergency in Orange County on Saturday, May 23, to open additional shelter sites and mobilize resources, then asked President Trump on Sunday for a federal emergency declaration that would bring FEMA assistance and federal funding to the scene. California said nearly 800 first responders and emergency personnel were deployed. The crisis also triggered a class-action lawsuit against GKN Aerospace by at least two Garden Grove residents and a probe by the Orange County District Attorney’s office into what caused the leak.