Officials say California chemical leak shifts as 50,000 remain evacuated

Evacuation orders remained in place for about 50,000 people Sunday as crews confronted the possibility that a damaged chemical tank in Garden Grove could still fail in two very different ways: a spill or an explosion. The emergency at GKN Aerospace’s facility at 12122 Western Ave. had already stretched into its fourth day, with officials warning that the tank’s condition was changing but not yet safe.

Orange County Fire Authority Interim Chief TJ McGovern said crews found a possible crack in the tank during overnight reconnaissance, a development officials said could alter the response if it is confirmed to be relieving pressure. The discovery is why officials described the situation as on a “new trajectory,” but the risk was not gone. It may be shifting from a tank under rising internal pressure toward one where responders can determine whether a controlled release is possible, rather than facing an abrupt rupture.

The tank is estimated to contain 7,000 gallons of methyl methacrylate, a flammable industrial chemical used in plastics manufacturing. Earlier reporting described a 34,000-gallon storage tank that overheated and began venting vapors on May 21. Fire officials said the tank’s internal temperature climbed by about one degree an hour, rising from 77 degrees Friday morning to 90 degrees by Friday night and Saturday, while pressure relief valves no longer worked.

McGovern said the overnight operation let crews visually inspect the tank with subject matter experts, but the crack still needed validation. Orange County Fire Authority Division Chief Craig Covey had already described the emergency as the worst he had seen in 32 years of fire service, saying the remaining outcomes were effectively a total tank failure with a chemical spill or an explosion. That assessment kept the public-safety stakes high for evacuees, nearby workers and the surrounding neighborhoods in Garden Grove, Huntington Beach, Fountain Valley and Anaheim.

Gov. Gavin Newsom declared a state of emergency in Orange County on Saturday, directing Cal OES and other state agencies to support local responders and open state-owned properties and fairgrounds as possible shelter sites. Shelters remained open, including facilities at Golden West College in Huntington Beach and Los Amigos High School in Fountain Valley, as schools in affected areas were told to consider contingency plans if the crisis continued.

No injuries had been reported. GKN Aerospace said it was working with emergency services, specialized hazardous materials teams and authorities, and apologized for the disruption to residents and businesses. Disneyland in nearby Anaheim was not under evacuation orders, but officials said they were monitoring the emergency while the county waited to learn whether the tank’s changing condition meant the danger was easing or only taking a different shape.