Toxic chemicals rain from sky as terrifying leak at SoCal plant forces evacuations

A leak of toxic chemicals from a massive tank at a Garden Grove aerospace facility forced evacuations to be reissued on Friday, a day after residents were first ordered out of the area.

Firefighters on Thursday afternoon responded to a vapor release from a 34,000-gallon tank containing methyl methacrylate at the site on the 12100 block of Western Avenue, according to the Orange County Fire Authority.

The industrial chemical is used in plastics and manufacturing, officials said.

The leak occurred at the GKN Aerospace plant, KABC reported.

The tank’s temperature had increased, activating a relief valve designed to safely release vapors, according to OCFA.

An overhead sprinkler system was activated to cool the tank, and vapor conditions improved as the liquid’s temperature decreased, officials said.

Firefighters also used large unmanned firefighting hoses to help cool the tank while industrial cleanup contractors assisted with the next phase of the operation, according to OCFA.

Evacuation orders were initially issued for the area north of Garden Grove Boulevard, east of Monarch Street, south of Orangewood Avenue and west of Beach Boulevard.

Rancho Alamitos High School’s gym at 113351 Dale Street in Garden Grove was established as a reunification site for evacuees.

The orders were later lifted for residential areas, though street closures remained in place on Western Avenue from Garden Grove Boulevard to Chapman Avenue and on Lampson Avenue from Santa Rosalia Avenue, according to OCFA.

Officials reissued evacuation orders Friday morning as a precaution while mitigation work continued.

The new evacuation zone covered the area north of Garden Grove Boulevard, east of Springdale Avenue, west of Dale Street and south of Orangewood Avenue, OCFA said.

A notice that appeared to be sent to Garden Grove Unified families and was posted to Reddit said several campuses would be closed Friday, though the district notice could not immediately be independently verified.

The notice said the closures were tied to “ongoing containment efforts” related to the leak and listed Pacifica High School, Rancho Alamitos High School, and several elementary and intermediate schools among the affected campuses.

The notice also said emergency responders were evacuating a mile-radius area around Chapman Avenue and Western Avenue while crews worked to safely contain the incident.

“An inoperable valve on the tank has created additional operational challenges, preventing complete mitigation at this time,” the agency said.

OCFA said the facility and industrial crew representatives were continuing to manage the containment and removal process.

Garden Grove police, the Orange County Sheriff’s Department’s Station unit and OC Health were also supporting the response.

“We recognize that evacuations place a significant burden on our community,” OCFA said. “Yesterday’s cooling operation was successful, and the facility and industrial crews initially made progress toward product removal.”

The agency said updates would be provided as the situation develops.

The cause of the leak was not immediately clear.

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