Firefighter/EMT here. Our department has trained on hybrids (don't cut the big orange cable!)[0] but not electric per se. Doesn't matter. Unless there's someone in the car, we're going to stand back, let it burn, and keep it from spreading. Cars contain bigger hazards than batteries: Airbags are basically bombs, and gas lifters (the things that make the hatchback open smoothly) can become missles in a fire. And that…
I read the electric vehicle procedure and they say to cut the battery cutoff cable twice.
I thought that was interesting - I guess it makes sense you don't want to release that cable so the two ends fall back together and create a welding rig.