Emergency Crews Tackle Chemical Threat in Garden Grove, California

By May 25, 2026, emergency efforts continued in Garden Grove, California, with 50,000 residents still under evacuation orders. Crews worked diligently to prevent an explosion at an aerospace facility where a tank held a volatile chemical, methyl methacrylate (MMA). Officials expressed cautious optimism but acknowledged ongoing risks.

Potential Threat at GKN Aerospace Facility

The focus was on preventing a ‘thermal runaway’ reaction in the MMA tank at the GKN Aerospace facility. Such a reaction could result in dangerously high temperatures and pressure, possibly leading to an explosion.

Impact on Residents

Memorial Day weekend saw entire neighborhoods evacuated as authorities warned of potential explosions affecting nearby containers. Residents like Jackie Urquiza faced difficulties and uncertainty. Evacuated with her son, she spoke of the challenges, including a lack of clothing and medication. “We had no idea such hazards were near our home,” she shared. Awoken by emergency sirens, she felt overwhelmed while packing essentials.

Fellow evacuee Andrea Luna described her ordeal as “devastating,” with nights spent in a parking lot. “The hardest part is not knowing what to do next,” she said. Some, like Pavel Ramirez-Tellez, left so quickly they forgot shoes.

Progress and Remaining Risks

Emergency crews made progress when hazardous material teams inspected the tank, identifying a pressure-releasing crack. The interim Chief of the Orange County Fire Authority, TJ McGovern, confirmed that a Boiling Liquid Expanding Vapor Explosion (BLEVE) was unlikely. Yet, uncertainties remain.

Efforts continued to assess and control the core’s temperature, which had decreased from 100 to 93 degrees. Officials noted the persistent risk, highlighting the need for accurate temperature readings within the substance.

Evacuation orders stayed in place.

GKN’s Response

GKN Aerospace issued an apology for the disruption, acknowledging the incident’s impact on the community. The company has a history of environmental regulatory issues, having settled violations costing nearly $1 million in 2021.

Understanding MMA Risks

MMA, used in plastics and glass substitutes, is harmless when stable. However, Elias Picazo, a chemistry assistant professor, warned of its acute toxicity hazards, such as respiratory tract irritation upon inhalation.

Officials have not detected any environmental leaks or air toxicity. The Environmental Protection Agency corroborated no evidence of environmental contamination despite the tank crack.

The cause of the tank’s failure is under investigation, and two class-action lawsuits have been filed in relation to the incident.

Outlook

With high risks, the number of responders in the zone remains limited. McGovern emphasized the priority of safety, stating, “We have to proceed strategically.” No timeline for residents’ return has been established as safety assessments continue.