Thousands of Orange County residents were still under evacuation orders on Friday after a 34,000-gallon storage tank at GKN Aerospace in Garden Grove overheated and began venting vapors, creating a hazardous chemical incident that fire officials said they had not yet been able to fully stabilize. The tank contained methyl methacrylate, a volatile and highly flammable liquid used in acrylic plastics. By the end of the day, officials were describing the scene as an active crisis rather than a routine spill response.
The leak began around 3:30 p.m. Thursday at the facility on Western Avenue. Authorities first evacuated the surrounding area out of caution, then briefly lifted orders late Thursday night after crews spent hours cooling the tank and reducing vapor production. But by early Friday morning the Orange County Fire Authority said conditions had changed and the evacuation had to be reissued. Later that morning, the evacuation zone was expanded again as crews continued monitoring readings near the site.
Officials said the situation had escalated overnight because the tank remained unstable. Division Chief Craig Covey said crews had not been able to fully stabilize it and warned that there were only two possible end states left: the tank could fail and spill thousands of gallons of hazardous chemical into the parking lot, or it could undergo thermal runaway and explode. Fire officials also said the system had already activated as designed, releasing vapors through the top and triggering the sprinkler cooling process.
Even with that danger, authorities stressed that there was no active gas leak or toxic plume in the area Friday afternoon. That did not change the evacuation order. Instead, it underscored how much uncertainty remained about the tank's condition. First responders had been pulled back from the immediate area out of concern for their safety, and crews continued remotely spraying water onto the container to keep temperatures down while hazmat teams watched for further change.
The disruption spread well beyond the plant itself. Western Avenue remained closed between Garden Grove Boulevard and Chapman Avenue, and police maintained a heavy presence around the industrial area. Workers arriving Friday morning were turned away, and officials advised residents to avoid the area and use alternate routes such as Beach Boulevard. Evacuation centers opened at Freedom Hall at Mile Square Regional Park in Fountain Valley, Savanna High School in Anaheim and John F. Kennedy High School in La Palma. Orange County Planet Fitness locations also offered evacuees and first responders access to restrooms, showers, electricity and Wi-Fi.
No injuries had been reported as of the latest update, but officials said the cause of the overheating remained under investigation. The episode showed how quickly a single industrial tank can turn a neighborhood into a controlled emergency zone. In Garden Grove, the immediate public priority was not just preventing a release, but preventing the tank itself from crossing the line from overheated storage vessel to outright failure.
Officials also stressed the public-safety side of the response. The area around the plant was being treated as a live industrial exclusion zone, not just a chemical cleanup site, which is why police kept workers away from Western Avenue and why access restrictions could expand again if readings worsened. That caution reflected the central challenge of the day: keeping people out of harm's way while crews tried to cool a tank that had already shown it was unstable.
