An “all-night mission” to see if the threat of a catastrophic explosion at a malfunctioning chemical tank at a Garden Grove aerospace company has been eliminated is taking place Sunday evening into Monday, officials announced.
Division Chief Craig Covey of the Orange County Fire Authority said in an interview with freelance news organization OnScene.TV that firefighters had previously been unable to examine the top of the tank at GKN Aerospace on Western Avenue because of the fear of a massive blast.
For update, see: Garden Grove chemical tank no longer threat for catastrophic explosion, officials say
But overnight Saturday, they found a crack that may be relieving enough pressure to prevent a massive explosion that could damage buildings and release a toxic vapor cloud.
“That changes the trajectory of everything and reduces its potential impact on the earth,” Covey said. “I’m not saying it can’t explode. The difference is, like, a gas explosion in a building versus a bomb hitting it. So, once we remove that, that really decreases the impact footprint that we’re managing right now, and we can reevaluate our current evacuation.”
Interim Fire Chief TJ McGovern said in a video update on X on Sunday night that crews would conduct an “all-night mission” to confirm that the pressure in the tank has been released and that the worst-case threat is eliminated.
“We are not there yet,” he told the public. “Please help us. Stay out of the evacuation zone, let us run our operation and tomorrow we will give you an update on what occurred this evening.”
***INCIDENT UPDATE***
Note: Videos include AI-generated captions. While efforts have been made to ensure accuracy, some transcription errors may occur. pic.twitter.com/YQJaMS7vrZ
— OCFA (@OCFireAuthority) May 25, 2026
McGovern noted the crack in an earlier video report posted to OCFA’s X account on Sunday.
“Last night, this operation that we did gave us positive intel to make educated decisions today,” McGovern said. “We’re not there yet, but this was a step in the right direction.”
A spill from the collapse of the tank was another possibility officials had cited, one they said was preferable to an explosion.
Experts and emergency crews have been working since Thursday to try to prevent a potentially catastrophic chemical spill or explosion. More than 785 state and local emergency workers are assisting with public safety, evacuations, traffic, sheltering and environmental monitoring, Gov. Gavin Newsom said.
The tank is filled with 7,000 gallons of a highly flammable chemical called methyl methacrylate. Crews have so far been unable to find a solution to end the threat posed by the tank, whose blast could damage hundreds of homes and buildings in the area and create a toxic plume in the immediate area.
Tracking air quality near the tank
Air quality officials said they have not detected any contaminants in the area of the malfunctioning tank.
Jason Lo of the South Coast Air Quality Management District said measurements detected no contaminants near GKN Aerospace at 12122 Western Ave.
“We are happy to report that levels are completely normal in our measurements,” Lo said in a video update posted on X.
Harry Allen of the U.S. Environmental Protection Agency said 24 air monitors installed in the area also did not detect any contaminants.
The OCFA said the incident management team established an evacuation zone in consultation with the EPA and the OC Health Care Agency.
“Any areas outside of this zone are currently considered completely safe and day-to-day activities can continue as normal,” it announced.
A Garden Grove emergency hotline was operated at 714-741-5444, and an Orange County public information hotline was available at 714-628-7085.
***CRITICAL INCIDENT UPDATE*** pic.twitter.com/pYHEzRz5ge
— OCFA (@OCFireAuthority) May 24, 2026
Food charity providing assistance
The World Central Kitchen, which brings food relief to disaster areas and war zones, arrived in Orange County this weekend with food and water. It would supply 2,200 hot meals, the organization announced.
Organizers mobilized as soon as they heard about the chemical crisis, World Central Kitchen response director John Torpey said, and began delivering food as early as Saturday.
The global relief organization, which joined local volunteers providing meals, said they were ready to stay as needed.
Evacuations across Orange County cities
About 50,000 people were affected by evacuation orders in Garden Grove, Stanton, Westminster, Cypress, Buena Park and Anaheim, and some of them posted on social media about suffering financial hits. At least half a dozen law firms pledged to file lawsuits seeking class-action status on behalf of those affected.
As of Saturday evening, six evacuation centers were operating throughout Orange County. However, Freedom Hall at Mile Square Regional Park, Savanna High School and John F. Kennedy High School had reached capacity, according to city officials.
The following evacuation centers are operating:
• Los Alamitos High School, 3591 W Cerritos Ave., Los Alamitos
• Los Amigos High School, 16566 Newhope St., Fountain Valley.
• Golden West College: 15744 Goldenwest Street, Huntington Beach.
• Ocean View High School: 17071 Gothard Street, Huntington Beach.
• Savanna High School: 301 North Gilbert Street, Anaheim (full).
• John F. Kennedy High School: 8281 Walker Street, La Palma (full).
• Freedom Hall: 16801 Euclid St, Fountain Valley, (full).
Newsom declared a state of emergency in Orange County on Saturday afternoon.
The emergency proclamation by Newsom unlocks additional resources for local officials and directs state emergency operations officials to focus on supporting local authorities in grappling with the ongoing emergency.
“The safety of Orange County residents is the top priority,” Newsom said in a written statement. “We are mobilizing every state resource available to support local responders and make sure the community has what they need to stay safe.”
Potential blast zone made public
Officials released a map Saturday giving residents their first look at the potential ramifications of the tank’s failure.
If an explosion does occur, the resulting “severe damage blaze zone” would most directly impact a largely industrial and business zone to the west, north and south of the plant, according to an OCFA map.
However, what appears to be about 100 homes is also included in the “severe damage” zone to the east of the plant, along with what appears to be about 100 more residences — and portions of an elementary school campus — in the “moderate damage blast zone.”
OCFA Division Chief Nick Freeman, in a video about the map, explained that “severe damage” zone — the innermost circle of the map — represents areas where they would expect “severe structural damage and significant harm.”
Knott’s Berry Farm in Buena Park and Disneyland in Anaheim were both open this weekend, but park officials said they are monitoring any developments.
An operations map showing the expected impact zone of a possible explosion and chemical leak from a hazmat incident at GKN Aerospace in Garden Grove is posted at the incident command post in the parking lot at the Los Alamitos Race Track on Saturday, May 23, 2026. (Photo by Jeff Antenore, Orange County Register/SCNG)
Frustration and outrage grow
Frustrations boiled over Saturday as displaced residents and community leaders demanded answers from public officials and consequences for the company behind the potential disaster.
U.S. Rep. Derek Tran, D-Cypress, whose district includes the evacuated area, called for a “deep investigation” into the situation at GKN Aerospace, a manufacturer of parts for commercial and military aircraft.
Orange County District Attorney Todd Spitzer opened a tip line, asking anyone with information on how this crisis developed to come forward. Tipsters were asked to call the DA’s anonymous tip hotline at 714-347-8714, to email prosecutors at tipster@ocdistrictattorney.gov or submit tips online.
Stanton Mayor David John Shawver said his whole city should evacuate and that he wants the National Guard to patrol the city. The county would have to make that request. Stanton has about 40,000 residents.
How concerned should you be about methyl methacrylate?
MMA is widely used, particularly in the plastics and aerospace industries, so the substance’s toxicity for humans is tracked pretty closely. It is, for now, known to be an irritant, particularly for the lungs and heart. But it is not, at this point, a known carcinogen in humans. That said, the toxicity in the event playing out in Garden Grove could ramp up quite a bit — and become lethal — if people are exposed to enough of the chemical.
If large amounts of MMA are spilled from the vats or released into the air following a fire or explosion, the public could be in danger of illness or powerful irritation, said Michael Kleinman, a professor at UC Irvine who teaches at the Joe C. Wen School of Population and Public Health. The chemical is particularly tough on the human respiratory system and, depending on how much a person inhales, MMA can cause everything from sore throats and cough to dizziness, nausea and, at the highest levels, damage to the nervous system, Kleinman said.
Those most at risk are people who already struggle with respiratory issues, such as asthma and people who have worked with MMA have developed allergies to the chemical over time. That means people in some jobs, including plastics and aerospace manufacturing, and working in nail salons, could be primed for a negative reaction if they’re exposed in this event, Kleinman said.
Officials have said that residents and communities outside the evacuation zone are not in danger of exposure.
What you should know about GKN Aerospace
The GKN facility has been operating in Garden Grove since 2004. It is primarily known as a worldwide leading manufacturer of cockpit windshields, jet canopies and aviation windows for civil and military aircraft. The site, which employs 540, even developed a line of special bullet-resistant glass. The company itself is based in the United Kingdom.
GKN paid nearly $1 million to settle numerous environmental violations in 2021, including failing to keep emission records and operating equipment without a permit.
Following an on-site inspection in November 2020, the South Coast Air Quality Management District cited GKN Aerospace in 2021 for failing to maintain required emission records for volatile organic compounds, which are gases emitted from paints, coatings and solvents. The South Coast AQMD is a regional agency responsible for regulating air quality in Southern California.
Trash pickup delayed
CR&R Environmental Services said its trash pickup will be delayed even in cities well outside the evacuation zone because its offices on Western Avenue near the aerospace company are closed and its trucks cannot be removed.
“Due to the ongoing chemical leak impacting our area, the operating facilities and Customer Service Center have been evacuated since (Friday), and services are currently on hold until we are granted safe access back to our facilities,” the company said in a Facebook post.
The communities affected are Costa Mesa, Irvine, Lake Forest, Laguna Beach, Laguna Woods, Midway City, Newport Beach, Orange, Roosmoor, Stanton, Tustin, Westminster and Artesia.
CR&R advised customers to seek updates at crrwasteservices.com.
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CORRECTION: Due to a reporting error, a story published Sunday, May 24 was incorrect when it said FEMA was preparing to offer hotel stays. The document was a FEMA Daily Operations Briefing that listed potential preparations for a 14-day mass care event.
A FEMA spokesman said, “We are actively monitoring the situation at the chemical plant in Garden Grove, California. We have received the governor’s request for an Emergency Declaration, and it is currently under review. We urge all impacted residents to stay vigilant, follow direction, and advise from local and state authorities, and stay safe.”
This story has been updated to show the correct year that GKN was established in Garden Grove.
