The tank contained 26,000 litres of methyl methacrylate, a volatile and flammable liquid used to make plastics, with firefighters warning the situation was looking grim.

About 40,000 people are under evacuation orders and schools have shut down in Southern California due to a hazardous chemical leak.

Authorities in Orange County say they’re unable to control the valves on a tank that contains methyl methacrylate, a chemical used in the manufacture of plexiglass.