The temperature of chemical tanks at an aerospace factory in a suburb of Los Angeles continued to rise after the area was evacuated following a fire, according to Los Angeles fire officials. Firefighters were working to prevent a major explosion at the Southern California facility, and officials told Reuters on Saturday that one of the chemical tanks was heating up despite continuous cooling efforts.

California Governor Gavin Newsom has announced that he has declared a state of emergency for Orange County due to the escalating crisis. The mandatory evacuations for tens of thousands of people in Garden Grove, a tightly packed suburb about 30 miles south of downtown Los Angeles, remain in place, as officials try to reinforce warnings that residents should stay away from the coast. Officials have been trying to hammer home the message for residents in the heavily populated Garden Grove area not to enter the beach zones, as mandatory evacuation orders remain in effect for tens of thousands of residents living in a coastal suburb about 30 miles south of downtown Los Angeles. The outbreak of the incident was reported to have been at the GKN Aerospace manufacturing plant, where the company makes windows and canopy panels for military and commercial aircraft. First responding personnel from the Orange County Fire Authority (OCFA) responded, locating an industrial storage tank, about 7,000 Aerial drone assessments of the vessel were initially made on Friday, which indicated that millions of gallons of water were continually being sprayed through unoccupied, remotely piloted hoses, helping to keep the vessel stable. But incident commander, and OCFA Division Chief Craig Covey, said those outside readings of the drone were very misleading. 

Covey explained in the video update that the drone readings were of the outside of the vessel and not of a chemical inside. Emergency crews embarked on a special nighttime mission, which was considered high-risk, to conduct on-site inspections to confirm the information. When they arrive at the manual gauge on the tank, the inside temperature is up to 90 degrees Fahrenheit (32 degrees Celsius), which is a lot hotter than it was when they at first had to flee. The temperature is currently rising inside the chemical at a rate of about one degree per hour. “Unfortunately, that's the bad news,” said Covey. 

Chemical liquid: Methyl methacrylate, highly volatile, flammable, extremely important for the plastics and resin industry. The experts state that the substance has self-heating properties, which allow for an exothermic reaction – as the temperature increases, the rate of polymerisation increases. This phenomenon can lead to an "uncontrolled thermal runaway" without suAicient intervention that increasingly raises the pressure until the container structure violently crushes. 

Emergency personnel have said there are two very hazardous situations at which they are grappling: the tank might crack under pressure, resulting in a huge leak of toxic chemicals, or the tank may explode entirely. If a blast occurs, it could not only injure the immediate area but also weaken and damage another 15,000-gallon chemical tank across the border, leading to a chain-reaction chemical disaster. 

As the radius of the explosion has increased, the crews have changed from a “defensive” cooling eAort to an “oAensive” approach overnight. With the assistance of specially-trained chemists from the manufacturing company's fire response team, firefighters went back in, where they helped to neutralise the adjacent storage tank and minimise its explosive capability if the smaller tank had failed. 

At the same time, responders are preparing sandbags, dikes and containment dams throughout the commercial site. These barriers are intended to capture the liquid for holding and not to allow toxic liquids to flow into local storm drains, river channels or the Pacific Ocean. 

The increasing danger has devastated the community. Municipalities such as Anaheim, Cypress, Westminster and Fountain Valley, which have been set up as evacuation centres, are reportedly at capacity. Board of Supervisors President Benjie Richmond said he has been told that the emergency call has pushed everyone but an estimated 15% out of their homes in the affected area, while 10,000 to 15,000 are believed to have stayed home. Garden Grove Police Chief Amir El-Farra said that while tens of thousands have obeyed the emergency call, an estimated 15% of Garden Grove residents are still inside their homes. 

The local health authorities have expressed serious concern about the public being exposed. Methyl methacrylate vapour is heavier than air; it will spread in the floor and settle next to ground level. Excessive exposure to the gas may cause a shortness of breath, eye and skin irritation, dizziness, and nausea. Dr Regina Chinsio-Kwong, Orange County's director of the health care agency, urged residents to stay completely outside the boundaries and remain safe. 

A GKN Aerospace spokesman took it upon himself to say sorry in a public posting for the "huge impact on families and businesses" in an area. When asked to make an apology, the spokesman for GKN Aerospace responded that it was “a very tough situation on local families and businesses, and the company is “100 per cent committed to attending to emergency services and specialist hazardous material teams to find a resolution”. 

Fire officials are talking to chemical and structural engineers across the country to come up with an “outside-the-box” solution. “This thing can't just let it go and destroy it, it's unacceptable to us,” Covey said. "We're not just surrendering"