Authorities in Orange County, Southern California, ordered the evacuation of around 40,000 residents after a pressurised chemical tank at an industrial facility began overheating and raised fears of a possible explosion.The incident occurred at a site in Garden Grove operated by GKN Aerospace, which manufactures components for commercial and military aircraft.The tank contains between 6,000 and 7,000 gallons of methyl methacrylate, a highly flammable chemical used in plastic production.

According to the Orange County Fire Authority, the tank began venting vapours after overheating, while its pressure relief valves became damaged or blocked, preventing safe release or removal of the chemical.Fire crews attempted to cool the tank, but uncertainty remained about internal temperatures, with drone readings suggesting rising heat levels.

Officials warned that continued heating could increase pressure further as the substance transitions from liquid to gas, raising the risk of rupture or explosion.Evacuation orders initially affected Garden Grove but were later extended to parts of Cypress, Stanton, Anaheim, Buena Park and Westminster.Several shelters were opened, including at local schools, as residents were told to leave their homes.Some individuals reported frustration and stress due to the disruption and uncertainty.

Experts warned that an explosion could spread toxic material over a wide area, while a controlled leak would be less severe than a catastrophic blast.However, deliberately breaching the tank was considered too dangerous due to ignition risks.Drone monitoring and containment barriers were deployed to track conditions and prevent potential contamination of waterways.The Governor of California declared a state of emergency, enabling additional resources to support local authorities.Officials also noted that nearby Disneyland was not under evacuation orders but was monitoring the situation.

Environmental and safety specialists highlighted the chemical’s flammability and health risks, including respiratory and neurological effects upon exposure.