Fire crews were called to the GKN Aerospace plant on Western Avenue in Garden Grove at about 3:22pm on a Thursday, after reports of a chemical release. What they found was a 34,000-gallon tank venting methyl methacrylate (MMA), an industrial liquid used to make acrylic plastics and composite materials. The Orange County Fire Authority confirmed the substance. Aerial footage showed the tank letting hazardous material into the air.
The evacuation that followed grew large. The BBC reported that tens of thousands of people were placed under evacuation orders as a precaution, and that Gov. Gavin Newsom declared a state of emergency. Garden Grove, Stanton, Anaheim, Cypress, Westminster and Buena Park were all affected. Some schools closed, and exits from several major roads were shut. Disneyland sat outside the zone and ran as normal.
A tank under pressure
The BBC described the tank as failing, with a risk of either a major spill or an explosion. Crews spent an overnight shift assessing it, and sprayed it with water to steady its temperature after some rapid heat increases. Officials were hopeful that pressure inside was being relieved gradually through a crack that had formed. The fire authority denied there was more than one.
“Continuous live atmospheric monitoring confirms there are no chemicals leaking,” the authority wrote in a social media post on Sunday evening, and fire officials said there was “currently no active leak.”
The worry is a Bleve, short for Boiling Liquid Expanding Vapor Explosion. Interim fire chief TJ McGovern said the all-night mission aimed to confirm the pressure was released so the threat was “eliminated”. He called a Bleve “the worst-case catastrophic event that we’ve been talking about. We are not there yet.” He also urged locals to stay out of the evacuation zone.
Division chief Craig Covey said earlier that officials hoped to slow the chemical reactions heating the tank. “Letting this thing just fail and blow up is unacceptable to us,” he said. Crews were also building dykes and dams under “very aggressive plans” in case the tank gave way, to keep chemicals from storm drains and the ocean.
Residents and health advice
Buildings between Western Avenue and Beach Boulevard, and between Garden Grove Boulevard and Orangewood Avenue, were cleared, according to guidance reported by ABC7. A reunification and support centre opened at Rancho Alamitos High School.
Mark Olsen told NBC LA he was woken by sirens, then told to leave. “It’s just frustrating,” he said of not knowing when he could go home. Others posted online about alerts that came with little warning and helicopters overhead. Those accounts are anecdotal.
Orange County health officer Dr Regina Chinsio-Kwong said inhaling the vapour could cause respiratory issues, eye irritation and dizziness. Anyone noticing “a fruity and heavy smell” should alert authorities. “Smelling it doesn’t mean you’ve reached a level that causes symptoms,” she said, “but we don’t want you to smell that.” People outside the one-mile evacuation zone should be safe, she added.
The facility sits about 35 miles (56km) south-east of Los Angeles. GKN Aerospace, a UK-based aircraft parts supplier, said it was working round the clock to reduce the risk of a leak and “sincerely” apologized to the local community. The cause remains under investigation, and no injuries had been reported when the first accounts were written.
Sources
- Chemical Disaster in Garden Grove: Panic Erupts As 34,000-Gallon Tank Failure Sends Toxic Fumes Into the Air
- Currently no active leak from failing chemical tank, California officials say
