The GKN Aerospace chemical release class action.

What happened

Methyl methacrylate is a flammable, volatile liquid used to make plastics. When it overheats it can set off a runaway reaction and, in a sealed tank, a boiling-liquid explosion. At 3:22 p.m. on May 21 a refrigeration valve at the GKN facility failed and the tank began to heat and pressurize. Responders could not drain or neutralize the contents because internal valves had gummed up from the chemical reaction inside.

The Orange County Fire Authority ordered an evacuation the first night, expanded it the next day to nine square miles covering parts of Garden Grove, Anaheim, Buena Park, Cypress, Stanton and Westminster, and did not fully lift it until May 26. Roughly 50,000 people left their homes over Memorial Day weekend. A crack in the tank wall eventually relieved the pressure; the neighboring tank was neutralized by hand.

A record that was already there

This was not GKN's first warning. State regulators cited the facility for ten workplace-safety violations in 2018, fined it for failed safety inspections in 2019, and in 2021 the South Coast Air Quality Management District assessed roughly $1 million in penalties for environmental violations. Compliance notices were issued again in March 2025. The FBI and EPA are now investigating whether federal environmental crimes were committed.

Where the case stands

More than thirty lawsuits have been filed on behalf of over a hundred residents and businesses, class actions in federal court and individual actions in Orange County Superior Court, alleging GKN was negligent in maintaining the tank, its cooling system, its valves and its monitoring. Plaintiffs seek compensatory and punitive damages. GKN has said it "respects the legal process."

Who we represent

• Residents forced out of their homes for three to five days, and the cost of hotels, food and travel that came with it.
• People who suffered headaches, nausea, breathing problems or anxiety from the release and the evacuation.
• The roughly 3,000 businesses that had to close and the 3,000 more that lost most of a holiday weekend's revenue.
• Workers who lost wages because their employer shut down.
• Property owners with contamination, cleanup or diminished-value claims.

What a claim can recover

Evacuation and out-of-pocket costs, lost wages and business income, medical expenses, the disruption of being ordered out of your own home, property remediation, and, given the history of citations, punitive damages intended to make a repeat impossible.

Facts on this page come from public reporting, court filings and agency statements as of September 2026. We update it as the case moves. Nothing here is a promise about what any individual claim is worth.