Risk of large explosion at California chemical tank is 'off the table'

The risk of a "massive explosion" at a damaged chemical tank in Southern California has been "eliminated," local fire officials said on May 25, resolving what authorities described as a possible "worst-case catastrophic event."

"The threat of a [large explosion] is now off the table," said TJ McGovern, interim fire chief with the Orange County Fire Authority, in a video address, adding that evacuation orders will remain in place. The agency said that "there is still an ongoing threat to public safety."

Roughly 40,000 people were ordered to evacuate from Garden Grove, a city south of Los Angeles, after a tank storing a toxic industrial chemical overheated on May 21. Initial efforts to secure the tank failed, leading authorities to expand the evacuation zone as they warned the container could potentially "blow up."

On May 24, authorities discovered a crack in the tank holding 7,000 gallons of methyl methacrylate. Crews evaluated the container overnight and found that pressure had been released and its internal temperature had dropped, Orange County Fire Authority division chief Craig Covey said, calling the development "incredibly positive news."

It's unclear how long evacuation orders will remain in effect. No chemical leaks have been detected at the site, according to the Orange County Fire Authority.

Pamela and Grace Johnson arrived at a shelter in Huntington Beach late on May 23 after their neighborhood in Orange County came under evacuation orders. The pair said they scrambled to find a place to stay as public shelters filled up with evacuees.

“I feel like the preparedness wasn't there,” Pamela Johnson told The Desert Sun, part of the USA TODAY Network, adding that she was on the phone for three hours trying to get information about where to go.

"We were just glad to get somewhere and sleep," she said. "We kind of haven't slept for four days."

Cracked chemical tank prompts state of emergency, lawsuits

Emergency responders were first called to the GKN Aerospace manufacturing facility on May 21 after a reported vapor release of methyl methacrylate.

A damaged valve impeded authorities from stabilizing the tank, forcing emergency officials to issue multiple rounds of evacuation orders. City officials across Southern California opened shelters for residents impacted by the incident.

California Gov. Gavin Newsom declared a state of emergency in Orange County over the weekend and said he requested that President Donald Trump issue an emergency declaration.

A proposed class-action lawsuit has been filed against GKN Aerospace, which is based in the United Kingdom. The company issued an apology and said its employees were "fully focused" on working with emergency services to resolve the situation.

The Orange County District Attorney's Office said it established an anonymous tip line and online reporting form to gather information about the incident. Environmental Protection Agency Administrator Lee Zeldin said his agency is involved in the emergency response.

Methyl methacrylate is a volatile, flammable liquid often used in the manufacture of resins and plastics, according to the EPA. California health officials said no exposure to the product is expected as long as evacuation orders are followed.

Contributing: Dinah Voyles Pulver, Daniella Segura, Paris Barraza, Kate Franco and Kristin Scharkey, USA TODAY and USA TODAY Network.

Christopher Cann is a national news reporter for USA TODAY. Contact him at [email protected] or follow him on X @Chris__Cann.