Garden Grove chemical tank scare forces 50,000 residents to evacuate

Tens of thousands of residents across Garden Grove and nearby cities were forced from their homes after a 7,000-gallon tank of liquid methyl methacrylate at the GKN Aerospace facility on Western Avenue near Lampson Avenue began overheating, bulging and venting pressure. Fire officials warned that the tank could crack, leak or rupture into a boiling liquid expanding vapor explosion, or BLEVE, and said the heat could spread to nearby tanks holding the same chemical.

By Monday, the Orange County Fire Authority said the worst-case scenario had been avoided. Crews had identified a crack that appeared to be relieving pressure, and the tank’s temperature had stabilized at about 93 degrees after climbing into a volatile range of roughly 90 to 100 degrees. Even with the immediate danger reduced, officials had not said what caused the tank to overheat, leaving the central failure point unresolved inside a facility that handles large volumes of reactive industrial material.

The evacuation reached about 50,000 people in Garden Grove, West Anaheim, Cypress, Buena Park and Stanton. Garden Grove police said roughly 15% of residents asked to leave refused evacuation orders as officers went door to door and relied on reverse 911 calls to clear the area. State officials also said that as of their May 24 update, there was no known leak of chemicals on the ground or in the air, a key reassurance for residents worried about exposure as the incident unfolded.

Governor Gavin Newsom declared a state of emergency in Orange County on May 23, directing Cal OES and other state agencies to support the response, open shelter resources and coordinate with local officials. By May 24, California said it had mobilized more than 785 state and local responders, including three specialized hazmat teams, 421 law enforcement officers, 170 firefighters and 30 CHP officers. On May 25, President Donald Trump approved California’s request for a Presidential Emergency Declaration, adding federal support to an already massive operation.

Methyl methacrylate can irritate the eyes, skin and respiratory system, and officials said vapors become hazardous if the compound overheats or polymerizes. For Orange County, the episode became a test of whether emergency systems could move fast enough to protect neighborhoods packed around industrial sites, and whether local and state oversight can keep a chemical tank scare from turning into a large-scale disaster.