Crews in Southern California work to prevent possible chemical tank explosion

ORANGE COUNTY, Calif. (NBC, KYMA) - Thousands of people in Orange County remain under evacuation orders as crews work to prevent a possible chemical tank explosion at a Garden Grove aerospace facility.

About 50,000 residents have been told to stay out of the area as firefighters continue cooling an overheating tank containing thousands of gallons of a flammable chemical known as methyl methacrylate.

Authorities warn a potential explosion or toxic spill could impact nearby neighborhoods, and several evacuation shelters have already reached capacity.

Officials released a map showing possible blast and toxic exposure zones, with the are closest to the facility facing the highest risk of severe damage.

Firefighters say a possible crack in the tank may be helping relieve pressure as crews work overnight to eliminate the threat.