20,000 evacuated in Southern California chemical leak as officials say tank "is going to fail"

Orange County officials expanded evacuation orders in several cities on Friday afternoon after an industrial tank containing a flammable and toxic, self-heating substance started leaking at a Garden Grove aerospace facility.

The Orange County Fire Authority has expanded the evacuation zone to include areas north of Trask Avenue, south of Ball Road, east of Valley View and west of Dale Street. Officials said the orders are affecting residents in Garden Grove, Stanton and Cypress. The City of Buena Park also issued mandatory evacuation orders, spanning from Ball Road to Trask Avenue and Valley View Street to Dale Street. Residents in the Girl Tract are "urged to leave the area immediately."

OCFA officials said a tank carrying "very bad chemicals" is "actively in crisis." There are three tanks in total, with one of the three compromised. 

"There are literally two options left remaining, one, the tank fails and spills a total of about 6-7,000 gallons of very bad chemicals into the parking lot and that area, or two, the tank goes into a thermal runaway and blows up, affecting the tanks that are around it that have fuel or chemicals in them as well," the OCFA said. 

During a Friday afternoon news conference, stern warnings to the community continued as OCFA Division Chief Commander Craig Covey said it is not known how widespread and dangerous an explosion could be.  "That we don't know. We want to prepare for the worst, but expect for things to get better."

The timeline for when an explosion or leak could happen is also unknown. "This is not precautionary, this is going to happen…this thing is going to fail. We don't know when," Covey said.

Air quality remains a concern, but Covey said that there is not an active plume, and no air particulates are "compromising anybody."

Crews arrived at the facility in the 12000 block of Western Avenue in Garden Grove after receiving a hazardous materials call just before 3:40 p.m., according to OCFA. Firefighters said the company that operates out of the building develops plastic components for the aerospace industry. 

The chemical initially stayed at the same temperature. However, about four hours after firefighters arrived, it rose, causing a relief valve and sprinkler system to activate.   

The OCFA say crews initially made progress toward removing the product, but unfortunately, on Friday morning, they determined that the "tank that is in the biggest crisis is in fact unable to be secured and mitigated."

Officials said there is no active gas leak or plume in the area, but residents in the area should adhere to all evacuation orders.

Orange County has activated and staffed a public information hotline at (714) 628-7085. 

The leaking tank contained a chemical called methyl methacrylate, a flammable plastic epoxy that generates its own heat, according to OCFA. Firefighters said the sprinkler safety system is designed to cool off the tank if it starts leaking. 

The cause of the leak remains under investigation. It's unclear what caused the leak. No injuries have been reported. 

Evacuation centers:

Garden Grove: Garden Grove Sports & Recreation Center, 13641 Deodara Dr. 

Cypress: Cypress Community Center, 5700 Orange Ave.