Overview
- The incident began Thursday when crews found a pressurized storage tank at the GKN Aerospace Garden Grove facility overheating and venting vapors from roughly 6,000–7,000 gallons of methyl methacrylate.
- Firefighters have continuously sprayed the tank to cool it while crews were unable to relieve pressure because valves were reported broken or 'gummed up,' and internal temperatures at times climbed well above safe thresholds.
- Specialists conducting a late Saturday reconnaissance reported a potential crack that may be relieving pressure, and federal officials on Sunday said a low‑volume leak is now the most likely near‑term outcome.
- Mandatory evacuations covering about 40,000–50,000 residents remain in effect with schools closed and multiple shelters open, evacuees have filed lawsuits against GKN, and no injuries or elevated air readings have been detected outside the exclusion zone so far.
- State and federal teams have mobilized hundreds of responders to keep the tank cooled, monitor pressure and air quality, and prepare containment plans while investigations and community impacts such as lost housing, business disruption and property concerns continue.