Key Points
- Around 40,000 residents were ordered to evacuate across six Southern California cities
- Authorities warn that the leaking methyl methacrylate tank could rupture or explode
- Emergency crews race to stabilise overheating tank at aerospace facility
ISLAMABAD: Thousands of residents in Southern California remained under evacuation orders on Saturday after an overheating chemical storage tank at an aerospace manufacturing facility threatened to rupture or explode.
The warning has prompted one of the largest hazardous-material emergency responses in recent years in Orange County, according to media reports.
The emergency unfolded at a facility operated by GKN Aerospace in Garden Grove, a city about 50 kilometres south of Los Angeles.
The officials said a storage tank containing between 6,000 and 7,000 gallons of methyl methacrylate had entered a critical condition.
Methyl methacrylate is a highly flammable industrial chemical used in the production of plastics, acrylic materials and aerospace components.
Authorities warned prolonged exposure to its vapours could trigger severe respiratory complications, nausea and irritation.
Officials from the Orange County Fire Authority told The Guardian that the tank had become unstable after a damaged valve complicated efforts to safely release pressure and stabilise the chemical reaction inside the container.
Emergency crews feared the tank could either crack and release toxic material into nearby drainage systems or enter a “thermal runaway” reaction that could trigger an explosion affecting surrounding fuel and chemical storage units, they added.
Division Chief Craig Covey described the situation as unprecedented, saying specialists from across California and other parts of the United States were being consulted to prevent a catastrophic failure.
Firefighters continued spraying water on the tank using remotely operated equipment to reduce temperatures without exposing personnel to toxic fumes or blast risks.
Evacuation orders were expanded across parts of six cities, including Anaheim, Cypress, Stanton, Buena Park and Westminster, affecting an estimated 40,000 residents over a roughly nine-square-mile area.
Authorities established emergency shelters in Garden Grove, Anaheim and Cypress as schools and several public facilities within the evacuation zone are closed.
Police used reverse emergency calls, loudspeaker announcements and social media alerts to urge residents to leave immediately.
Despite repeated warnings, officials said nearly 15 per cent of residents in the evacuation area initially refused to leave their homes.
Health officials said air quality monitoring had, so far, not detected dangerous concentrations of chemical vapour outside the restricted zone, though authorities stressed the situation remained volatile and unpredictable.
Sandbag barriers were also deployed around the facility to prevent any potential spill from contaminating nearby storm drains and waterways.
The incident began on Thursday after emergency crews responded to reports of chemical vapour leaking from a much larger 34,000-gallon storage tank at the aerospace facility.
Initial evacuation orders were briefly lifted before officials received updated technical assessments indicating an elevated risk of explosion, forcing authorities to widen the evacuation zone on Friday.
No deaths or injuries had been reported as of Saturday, and authorities said efforts to stabilise the tank were continuing around the clock.
