Electric vehicles don’t catch fire very often, but when they do it’s really hard to put out, and the water used to do so is contaminated with lithium. Because of the chemical reactions occuring they can reignite spontaneously too. Some places they have giant containers that the car can be put into and filled with water, and there are also systems being developed to continuously flow water through the battery. It is definitely a major issue for fire fighters to deal with when it occurs.