A state emergency is in effect as crews monitor a damaged tank filled with methyl methacrylate.
GARDEN GROVE, CA — More than 50,000 people remained under evacuation orders Saturday after a damaged chemical tank at a GKN Aerospace facility threatened to spill or explode in a dense part of Orange County.
The emergency has pushed local, county and state officials into a high-risk response over Memorial Day weekend, with firefighters trying to cool and stabilize a tank holding thousands of gallons of methyl methacrylate, a flammable liquid used in plastics and manufacturing. Gov. Gavin Newsom declared a state of emergency for Orange County as crews worked with hazardous materials experts to keep the crisis from spreading beyond the industrial site.
Firefighters first responded Thursday night to the GKN Aerospace facility in Garden Grove after reports of a problem with a storage tank that had begun venting vapors. Officials said the tank later showed signs of serious stress, including rising heat and damage to valves that made it difficult to relieve pressure or move the chemical safely. Orange County Fire Authority Division Chief Craig Covey said the tank had two likely paths. “It fails or it blows up,” Covey said during a public update, describing the risk facing responders and nearby neighborhoods.
The evacuation area grew as officials warned that a failure could release about 6,000 to 7,000 gallons of methyl methacrylate or trigger an explosion that could affect nearby tanks and buildings. The orders covered parts of Garden Grove and nearby communities, including Cypress, Stanton, Anaheim, Buena Park and Westminster. Garden Grove officials listed an evacuation zone south of Ball Road, east of Valley View Street, west of Dale Street and north of Trask Avenue. No deaths or injuries had been reported, and officials said they had not detected an active gas plume during updates Saturday.
The chemical involved is widely used in resins, plastics and industrial production. Health officials said exposure to its vapors can irritate the eyes, nose and throat and may cause headaches, nausea or breathing trouble. Emergency crews set up containment barriers around the facility to keep any spill from reaching storm drains or waterways. Firefighters used remote equipment, water streams, drones and monitoring devices to limit the time crews spent near the tank. Officials said one gauge showed the tank temperature had climbed from 77 degrees Friday morning to about 90 degrees, with concern that heat was still rising.
The site, at a GKN Aerospace operation in an industrial area of Garden Grove, makes parts tied to aviation and aerospace work. The company said it was cooperating with emergency responders and apologized for the disruption to residents and businesses. The crisis also affected local schools, events and traffic. Several shelters opened across Orange County, including school sites used to house displaced residents. The broader Garden Grove area includes one of the nation’s largest Vietnamese communities, and officials issued emergency information in several languages as police and city workers tried to reach households inside the evacuation zone.
Newsom’s emergency proclamation made state resources available to local responders and opened the door for added shelter and support sites. Local officials said they were also consulting experts from outside the region because the tank could not be handled like a routine hazardous materials call. Crews were working to reduce the danger from another nearby 15,000-gallon tank while continuing to cool the damaged one. The Orange County District Attorney’s Office also began looking into the cause of the incident, though officials had not said Saturday what first caused the material to overheat.
The evacuation left many residents waiting outside the zone with few firm answers about when they could return. Some people left with pets, medicine and small bags, while others stayed despite warnings. Officials said the risk was not limited to the immediate fence line because a blast or large spill could move danger into nearby blocks. Garden Grove Mayor Steve Jones called the incident unprecedented for the city and said the response was focused on preventing a disaster before it happened. Fire officials said they understood the frustration but could not lift orders while the tank remained unstable.
By late Saturday, crews were still monitoring the tank and weighing possible ways to neutralize or transfer the chemical without setting off a larger failure. Officials said the next major update would depend on temperature readings, air monitoring and the condition of the damaged valves. Evacuation orders remained in place as the emergency entered Sunday.
Author note: Last updated May 24, 2026.