California Gov. Gavin Newsom declared a state of emergency in Orange County on Saturday as firefighters in Garden Grove worked to cool a 7,000-gallon tank of methyl methacrylate that the local incident commander said was nearing a thermal runaway explosion, with roughly 40,000 residents under evacuation orders across six cities.
The storage tank at GKN Aerospace's plastics facility began venting vapors Thursday afternoon and has resisted three days of cooling efforts. Internal temperatures climbed from 77 degrees Fahrenheit to 90 degrees by Saturday afternoon, rising about one degree per hour, Orange County Fire Authority Division Chief Craig Covey said. A rupture would send the toxic chemical into storm drains that drain to the Pacific; an explosion could ignite a 15,000-gallon tank of the same substance and a 4,500-gallon tank stored nearby.
Two bad options
Covey, the incident commander, said the agency was facing "possibly one of the worst chemical incidents in California history," he told NBC News on Saturday. At a Friday news conference he described only two outcomes: the tank fails and spills its contents, or it "goes into a thermal runaway and blows up, affecting the tanks that are around it that have fuel or chemicals in them as well." On Saturday he said crews were evaluating a third path. "Letting this thing just fail and blow up is unacceptable to us," he said.
Firefighters are running sprinklers and hose lines on the tanks and monitoring temperatures with drones every 10 minutes. Methyl methacrylate, used to make resins and aerospace plastics, is flammable and generates its own heat as it polymerizes. Crews on Saturday morning approached the tank in person and discovered internal temperatures far higher than the readings they had been taking through the 1-inch steel walls, Covey said.
Evacuations and air monitoring
Garden Grove Police Chief Amir El-Farra said evacuation orders cover roughly 40,000 people; CBS News, citing officials, put the figure above 50,000 as the zone expanded into Cypress, Stanton, Anaheim, Buena Park and Westminster. Disneyland, in neighboring Anaheim, remained open. The Garden Grove Unified School District closed 15 campuses indefinitely.
The Environmental Protection Agency has deployed 24 stationary air monitors that operate around the clock, and South Coast Air Quality Management District official Dr. Jason Lo said Saturday night that levels were "completely normal." Orange County Health Officer Dr. Regina Chinsio-Kwong said the chemical carries a fruity odor and can cause respiratory irritation, nausea and burning eyes for those who ignored the order.
The investigation
Orange County District Attorney Todd Spitzer opened a criminal investigation Saturday into the cause of the failure and urged GKN Aerospace employees to come forward. GKN Aerospace said it was "fully focused on working with emergency services" and apologized for the disruption.
Neither GKN Aerospace nor federal regulators had publicly addressed the maintenance history of the tank or the cause of the initial overheating by Saturday night, and Covey said it remained unclear whether state or federal authorities would deploy personnel to assist the county.
Rep. Derek Tran, who represents the district, asked Newsom to seek a federal disaster declaration that would activate the Federal Emergency Management Agency in the event of a catastrophic incident. No timetable has been set for residents to return.