Crack At GKN Aerospace Chemical Tank Triggers Emergency, Evacuates 50,000 In Garden Grove

A crack in a chemical tank at the GKN Aerospace facility in Garden Grove, California, triggered a state of emergency and evacuation orders for 50,000 residents as emergency response teams worked to prevent a potentially explosive situation.

The tank, located in the southeastern corner of the GKN Aerospace facility, holds around 7,000 gallons of methyl methacrylate, a highly toxic and highly flammable chemical used in the manufacturing of resins and plastics.

ABC News

Orange County Fire Authority interim chief TJ McGovern said firefighters approached the tank to "get eyes" and found "a potential crack in the tank" after the chemicals began to exceed a safe temperature.

NBC News reported that the tank started to heat up and bulge last week, prompting concerns it would rupture and either explode or leak, and that the crack was identified Saturday night during a visual inspection of the 7,000-gallon tank.

Officials said the tank was being continuously sprayed with water to keep it cool, and that the incident began Thursday, with the risk centered on pressure buildup from methyl methacrylate reacting exothermically.

By Monday, officials said the risk of a devastating vapor explosion had been avoided, with Orange County Fire Authority interim chief TJ McGovern posting that "the threat of a BLEVE is now off the table".

Craig Covey, the Orange County fire incident commander, said the temperature inside the tank had dropped from 100 degrees Fahrenheit to 93 degrees after the crack was identified Saturday night and crews continued cooling operations.

ABC News

CBS News said California Gov. Gavin Newsom issued a State of Emergency for Orange County and asked President Trump for a federal emergency declaration, which Trump approved on Monday.

The Orange County Fire Authority said it was "re-evaluating" evacuation zones after the threat of the BLEVE being eliminated, adding "Please do NOT enter the evacuation zones at this time."

ABC News reported that while the catastrophic explosion threat was eliminated, evacuation zones were still in play and officials told residents to "Please abide by those evacuation zones."

Even with the BLEVE threat eliminated, officials said evacuation orders remained in place for about 50,000 people in Garden Grove, and Orange County Fire Authority said the risk to public safety was "ongoing".

Andrew Whelton, a Purdue University engineering professor, cautioned that there was still some risk of an explosion while the chemical inside the tank remains hot and reactive, and said temperatures needed to fall closer to ambient levels — roughly 60 to 70 degrees Fahrenheit — before conditions were significantly safer.

The Associated Press reported that authorities detected no hazardous chemical levels as of Monday and that officials needed to cool the tank to prevent a toxic leak or explosion, while drones monitored conditions and containment barriers were set up to prevent chemical from reaching storm drains or the ocean.

NBC Los Angeles reported that a White House official said the U.S. EPA enabled air monitoring at 20 locations around the area and that FEMA deployed a Liaison Officer and activated its Interagency Modeling and Atmospheric Assessment Center.

The Associated Press also reported that some Garden Grove residents filed a class-action federal lawsuit against GKN Aerospace Transparency Systems, and that GKN Aerospace agreed in 2025 to pay state regulators more than $900,000 to settle violations involving recordkeeping, permitting issues and nitrogen oxide emissions.