Sri Lanka, May 24 -- California Governor Gavin Newsom has declared a state of emergency as crews race to contain a toxic chemical leak at a manufacturing facility in Orange County.

A tank containing about 7,000 gallons of methyl methacrylate, a highly volatile and flammable substance used to make plastic, was at risk of failure, officials warned. Thousands of Garden Grove residents are under evacuation orders as a precaution.

Officials said on Saturday that the temperature in the tank was higher than previously thought and it was continuing to rise.

Orange County Fire Authority division chief Craig Covey said they were planning for two scenarios: "Does it rupture and spill, or does it blow up?"

The aerospace facility is about 5 miles ...