A Tesla car battery "spontaneously" burst into flames on a California freeway Saturday, and firefighters needed 6,000 gallons of water to put it out.

The Metro Fire Department said in a series of tweets that "nothing unusual" had occurred before the Tesla Model S became "engulfed in flames," but the agency said the car's battery cells "continued to combust" while the fire was being extinguished.

No injuries were reported.

In 2021, the National Highway Transportation Safety Administration (NHTSA) declined to open an investigation into Tesla car battery fires, calling them "rare events."

A handful of studies have shown electric vehicles are less likely to catch fire than gasoline or hybrid-electric vehicles — but that when they do, they burn hotter and longer.