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All evacuation orders lifted, no threat of explosion, fire or leak at Garden Grove chemical tank

Last updated: Wednesday, May 27, 2026 7:42AM GMT
All evacuation orders lifted in Garden Grove chemical tank crisis

GARDEN GROVE, Calif. (KABC) -- There is no longer a threat of explosion, fire or chemical leak for a damaged tank at the GKN Aerospace facility in Garden Grove, the Orange County Fire Authority announced on Tuesday night.

All evacuation orders were officially lifted at 7:30 p.m., allowing the final 16,000 evacuated Orange County residents to return home. Initially, 50,000 residents were evacuated from their homes last week.

A tank carrying 6,500 gallons of the highly toxic chemical methyl methacrylate (MMA) became unstable last week, causing the tank to heat up uncontrollably. For a few days, officials said the tank would either explode or spill out, and either outcome was inevitable.

Eventually, the tank cracked, allowing the pressure to release and eliminating the threat of a BLEVE, which stands for Boiling Liquid Expanding Vapor Explosion.

Then, crews worked a risky mission to confirm that the pressure had been released and to remove weather insulation from the outside of the tank to help the water be more efficient at cooling the temperature down.

Still, a threat remained for a fire or a small explosion. Firefighters continued to try to get the tank to stabilize and were eventually able to stop dousing it with water. On Tuesday afternoon, crews were seen freely walking around the tank and climbing on top of it.

By Tuesday night, OCFA declared that there was no longer a risk to surrounding residents and all evacuation orders were lifted. No injuries were reported.

The investigation into what caused the material in the tank to overheat is ongoing. Residents have already filed a class action lawsuit against GKN Aerospace.

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KABC logo
May 26, 2026, 3:24 AM GMT

How OC officials created new evacuation map, mitigated risk of explosion

Officials provided a positive update on Monday evening, saying the worst-case scenario at an unstable chemical tank has been avoided.

Officials provided a positive update at a press conference on Monday evening, saying the worst-case scenario at an unstable chemical tank in Garden Grove has been avoided. With the announcement came a reduction in the evacuation zone for Orange County residents.

"The most catastrophic and worst-case scenario was mitigated and resolved," Orange County Fire Authority Interim Chief TJ McGovern said. "That was the case of a potential BLEVE (Boiling Liquid Expanding Vapor Explosion). It's not over yet, and I want to re-emphasize that. It's not over yet. We still have work to do."

McGovern said the reduced evacuation zone is still in place because crews are still working to mitigate the chance of a small explosion, fire, or possible spill. Approximately 16,000 residents are still impacted.

OCFA Chief Craig Covey provided new details about what firefighters have been doing to improve the situation at GKN Aerospace. He said firefighters were specifically approaching the tank and checking the trends overnight because the temperature is the most unstable during the daylight hours.

He said when the tank cracked, it was just enough to release the pressure without causing a leak or an explosion. Now, the internal temperature of the tank is finally reducing as the tank stabilizes. The tank previously reached over 100 degrees, hotter than their gauges could measure.

Covey said overnight, firefighters took off weather protection and insulation on the outside of the tank to help the water be more efficient at cooling the temperature down.

He stressed that there have been no injuries to civilians or firefighters throughout the ongoing incident.

The tank initially held approximately 6,500 gallons of a toxic chemical, methyl methacrylate, or MMA. Now, officials believe a lot of the chemical has cured.

"We don't think there's that much liquid potential left in it. We don't know exactly how much... we know some of that is gelled up or hardened like it's supposed to do," Covey said.

Authorities explained that the reduced evacuation zone was established with residents' safety as the top priority. Covey said the county's team of experts is focusing on a five-day risk assessment, keeping the weather forecast in mind. The new, reduced evacuation zone also takes into consideration the risk of a potential plume or fire at the tank.

In order to further reduce the evacuation zone or eliminate it completely, Covey said they need to continue to observe a trend of decreasing temperatures inside the tank. That's what will decrease the risk of fire.

He said there is no timeline for when the evacuation zone will be reduced again, but said it will not happen on Monday.

"The city remains committed to understanding what happened, supporting those impacted, and working with the appropriate agencies to make sure this incident is fully reviewed," Garden Grove Mayor Stephanie Klopfenstein said at Monday's press conference.

Klopfenstein noted that Tuesday's regularly scheduled city council meeting has been canceled, and instead, the city will hold a special meeting at the Community Meeting Center at 5:30 p.m., focused on the incident, the city's response and the latest information available. Residents are encouraged to attend and ask questions.

KABC logo
May 26, 2026, 2:48 AM GMT

'No contamination': OC officials say residents going home don't need to worry about fumes

"You can feel safe. There was no contamination. There were no fumes. There were no vapors that came from this incident," Health Officer Dr. CK said.

With thousands of Orange County residents returning home on Monday evening, local leaders and experts are ensuring that everyone can go home feeling safe.

Orange County Health Officer Dr. CK said there were no fumes and there are no vapors in the air that could harm residents.

"When you go home, you can feel safe. There was no contamination. There were no fumes. There were no vapors that came from this incident. There was no leak. You should feel comfortable going home," Dr. CK said at a Monday evening press conference.

Officials are stressing that there has been no leak of contaminants into the air. Chris Myers with the EPA said 20 real-time air monitoring instruments have been working around the clock throughout the evacuation zone. He said no exceedances have been detected at any time throughout this event, and air monitoring will continue.

Authorities say residents also do not need to worry about particles settling around their homes since the air quality has been consistently clean. There is no need to wipe down patio furniture or any belongings exposed to the open air.

In addition to safe air quality, officials are ensuring that the water quality is also unaffected. The Orange County Fire Authority said runoff flowing from the water being sprayed on the tank and into storm drains is beeing consistently tested, and it has been clean the whole time. If contaminants were to enter the water, OCFA Chief Craig Covey said downstream barriers are in place to capture anything floating in the water. Still, the barriers have not collected anything so far since the water remains clean.

Approximately 16,000 residents remain in a reduced evacuation zone.

KABC logo
May 26, 2026, 3:02 AM GMT

Map shows reduced evacuations impacting 16,000 Orange County residents

The evacuation zone for a chemical tank crisis unfolding in Garden Grove for the past several days has been reduced.

The new zone impacts 16,000 residents. The new map barriers include Orangewood Avenue to the north, Dale Street to the east, Knott Street to the west and Garden Grove Boulevard to the south.

Evacuation shelters will remain open for the residents who live within the reduced evacuation zone.

Previously, 50,000 Orange County residents were within the evacuation zone.

KABC logo
May 26, 2026, 3:03 AM GMT

Thousands of OC residents can return to homes as evacuation zone is reduced

At a press conference on Monday evening, Orange County Fire Authority officials announced that the evacuation zone for the chemical tank crisis unfolding in Garden Grove has been significantly reduced.

OCFA shared the new map in a post on social media. Approximately 65% of the impacted residents are now able to return home.

The new map barriers include Orangewood Avenue to the north, Dale Street to the east, Knott Street to the west and Garden Grove Boulevard to the south.

Garden Grove Boulevard will restore flows of traffic in the eastbound and westbound directions. All off- and on-ramps of the 22 Freeway will also remain open.

Orange County officials said the new, reduced evacuation zone takes into consideration the risk of a potential plume or fire at the tank.

In order to further reduce the evacuation zone or eliminate it completely, OCFA Chief Craig Covey said crews need to continue to observe a trend of decreasing temperatures inside the tank. That's what will decrease the risk of fire.

Officials said a high police visibility will remain in the area.

Evacuation shelters will remain open for the approximately 16,000 residents still within the reduced evacuation zone.