A major hazardous materials incident continues in Garden Grove after a large industrial storage tank containing methyl methacrylate (MMA) entered what fire officials are describing as a potentially catastrophic condition.
The incident began Thursday afternoon, May 21, 2025, at the GKN Aerospace facility near Western Avenue and Lampson Avenue in Garden Grove. According to the Orange County Fire Authority (OCFA), crews responded after a 34,000-gallon storage tank containing MMA — a highly flammable and toxic chemical used in the production of acrylic plastics and aerospace components — began overheating and venting vapors into the air.
As conditions worsened overnight and into Friday, evacuation zones were expanded dramatically, eventually affecting portions of Garden Grove, Anaheim, Stanton, Cypress, Westminster, and Buena Park. Thousands of residents were ordered to leave the area while schools and businesses shut down across the region.
During a Friday afternoon press conference, OCFA Division Chief Craig Covey delivered a stark warning about the seriousness of the incident.
“This thing is going to fail, and we don’t know when,” Covey said. “There are literally two options left remaining. The tank fails and spills thousands of gallons of very bad chemicals, or the tank goes into thermal runaway and blows up.”
Officials stated that crews have been attempting to cool the tank while hazardous materials specialists work to stabilize the situation. Sandbag containment barriers have also been constructed to prevent chemicals from entering storm drains or waterways if the tank ruptures.
Garden Grove Mayor Stephanie Klopfenstein urged residents to take the evacuation orders seriously, saying:
“We understand that this is frightening, but the evacuation orders are in place for your safety.”
The incident has drawn an enormous multi-agency response involving:
• Orange County Fire Authority Fire Department and HazMat Teams
• Garden Grove Police Department
• Orange County Sheriff’s Department
• Cal OES
• FEMA and EPA coordination personnel
• Industrial hazmat contractors and environmental cleanup teams
For scanner listeners and radio hobbyists, this incident also highlights the continuing loss of monitorable public safety communications in Orange County. Most OCFA, police, and sheriff communications are now fully encrypted and cannot be monitored directly by scanners.
Some limited monitoring may still be possible through:
• Broadcastify feeds
• PulsePoint incident data
• Media helicopter feeds
• Aircraft and aviation frequencies
• Public works and interoperability channels
• Official agency social media accounts
At this time, no injuries have been reported. However, officials continue warning that the tank remains unstable and that the situation could rapidly deteriorate.
Residents are strongly urged to avoid the affected areas and comply with all evacuation orders and road closures.