On Saturday, firefighters in Southern California were cooling a tank that was “literally on edge” of blowing up as they attempted to avoid a potentially disastrous “worst” scenario. Subscribe to this story to enjoy it ad free

Enjoy unlimited access to exclusive articles and ad-free content. Chief Craig Covey of the Orange County Fire Authority told NBC News Saturday that the 7,000-gallon methyl methacrylate tank, a toxic substance used in resins and other plastics manufacturing, could cause an explosion to occur nearby, which would then ignite a 15,000 gallon tank containing the same chemical. “We are talking about one of the worst incidents ever in California chemical history,” said Chief Craig Covey.

Gov. Gavin Newsom declared an emergency on Saturday in Orange County, and instructed his Office of Emergency Services to provide assistance to the affected residents. Covey stated that the problems

have been reported from Garden Grove, California and parts of nearby cities include loss in valve control and rising temperatures inside the tank, which has already reached a volatile range of 90-100 degrees Fahrenheit. He said that these temperatures could be the beginning of a “thermal explosion” if they continue to rise. “We are literally at the edge,” he said. An Orange County Fire Authority Firefighter tells a photogrher that he must evacuate the GKN Aerospace site in Garden Grove on Friday. Allen J. Schaben/ Los Angeles Times, via . On Saturday, firefighters continued to cool the facility with sprinklers. They hope the process will cause the chemical to “cure” and slow down its heating enough to prevent a blast. Covey warned that a “worst scenario” could see the three tanks, including a 4,500 gallon tank, explode. The OCFA stated in a press release that the hazmat event began with a “vor leak” from the 7,000-gallon storage tank at the facility. Covey explained that first responders from GKN Aerospace could have measured incorrect temperatures because they were taking them outside the 1-inch thick steel wall of the tanks. On Saturday morning, firemen got dangerously near the stored chemicals, and they discovered that they could measure an internal temperature much higher than anything they had seen before, Covey said. Covey stated that the new assessment showed tank temperatures increasing from 77 degrees to 90 degrees, an increase of about 1 degree per hour on Saturday afternoon. “We’re trying to mitigate this,” he said. “The worst-case situation is that fireball.” Covey stated that officials are developing contingency plans. These include the possibility of preventing the chemical from entering storm drains and efforts to “dike it, dam it, and divert” it if this hpens. Covey told reporters that the situation was serious. This is real.

Orange County health officer Dr. Regina Chinsio Kwong said that those outside of the evacuation zone will not face any health risks. However, she warned at a Friday news conference that the incident was “a unique situation”. The emergency evacuation centre at Freedom Hall in Fountain Valley was set up on Saturday for residents living near the GKN Aerospace Transparency buildings. Allen J. Schaben/ Los Angeles Times via .

Garden Grove has been ordered to evacuate, along with the nearby cities of Cypress, Stanton Anaheim Buena Park, Westminster and Cypress. Amir El-Farra of the Garden Grove Police Department said on Friday that these orders affect about 40,000 people. Newsom’s emergency declaration opens up additional state resources like state-owned properties or fairgrounds to be used for sheltering evacuees.