California toxic chemical leak sparks explosion fears as 40,000 evacuated in 'crisis situation'

Emergency crews have issued an urgent warning about a chemical leak coming from a tank at Garden Grove aerospace facility in Orange County, after triggering evacuation orders for 40,000 residents and school closures.

Authorities have stated that the leak is a 'crisis situation' after the overheated tank is facing a potential catastrophic failure.

Approximately 40,000 residents in the Orange County area in California have been placed under evacuation orders, as officials are concerned that the tank, which is filled with a toxic chemical methyl methacrylate, is likely to either leak or explode.

The chemical, also known as MMA, is used to make plastics, but can potentially cause respiratory issues if humans are exposed to it, as per the Environmental Protection Agency.

The crisis began on Thursday (May 21), when the tank started venting vapors, with officials noting it appeared to bulge, indicating dangerous overheating and potential rupture.

Officials from the Orange County Fire Authority (OCFA) stated that a spill, though undesirable, would actually be the 'best-case scenario' compared to an explosion, which could cause a lot more damage.

Emergency crews are currently spraying the tank with water to decrease the temperature, and have installed sand barriers to contain any potential spill.

But despite officials urging those in the region to evacuate, Garden Grove police reported a 15 percent refusal rate among residents who have been asked.

The industrial site where the tank is located is around 5 miles from Disneyland.

OCFA Division Chief Craig Covey claimed that there are 'literally two options left remaining'.

***Incident Update***

Incident Commander Chief Covey provides an update on the hazardous materials incident in Garden Grove. Our next update will be provided tomorrow morning unless there is a change in incident status. pic.twitter.com/z8xns32iyS

— OCFA (@OCFireAuthority) May 23, 2026

Speaking to reporters, he said: "One, the tank fails and spills a total of about 6,000 to 7,000 gallons of very bad chemicals into the parking lot in that area, or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around them that have fuel or the chemicals in them as well."

Officials noted that air quality was being actively monitored in the area, and that currently, all readings were still within healthy limits.

Update on evacuation centers:

Garden Grove Sports and Recreation Center
13641 Deodara Dr.
Garden Grove, CA 92844

Cypress Recreation and Community Center
5700 Orange Ave.
Cypress, CA 90630

— OCFA (@OCFireAuthority) May 22, 2026

The evacuation zone covers the area north of Trask Avenue, south of Ball Road, east of Valley View Street and west of Dale Street, and centers have been established at the Garden Grove Sports and Recreation Center and the Cypress Recreation and Community Center.

Gov. Gavin Newsom's office said in a statement: "Our office continues to closely monitor the situation, and we urge residents in impacted areas to follow guidance from emergency officials."