A friend of mine works with a local hazmat team and told me another Tesla horror story. Apparently, the other day a Tesla veered off the road, hit a guard rail and caught fire. Luckily the driver was able to get out safely. However, the fire department recommended to just let the car burn because of how much water it would take for them to put it out because of the heat of the fire.
So the fire department just lets the fire burn out. Eventually it stops and they bring in a tow truck. They strap it on, and as they're loading it all 12,000 of the lithium ion battery rods spill out of the car. Now these are both hazardous waste and extremely volatile. So the hazmat team comes in and has to shovel up all 12,000 of these rods while wearing full flame proof gear in 90° F heat and put them into 55 gallon drums to get picked up as hazardous waste. All knowing that at any point, they could catch on fire.
These cars are so fucking ridiculous. Whenever I see them I stay far away on the road. Fuck Musk, electric cars are a mistake and an environmental nightmare.
The way to safe the battery cells and make sure they won't later short out causing a fire, is salt water. If the cells can be removed, just dumping them all in a container connected to ground and filled with salt water will make them safe. Once the battery cells were out of the vehicle it's probably why the hazmat team put them all in 50 gallon drums that I assume were filled with salt water. The reason they catch fire is due to electric shorting (either external or internal) but once fully discharged it is no longer an issue. At that point they are no longer a hazardous material but just dead ingots of graphite, steel, nickel, lithium carbonate, and trace amounts of cobalt.
This is done in more recent methods of lithium ion battery recycling happening in China because it ensures the cells are all in a state where you can safely grind them up then using electrolysis separate all the different metals without risk of fire. You don't see it done unless there are zero plans to reuse the battery cells or you need to know they are absolutely safe because it destroys them. Honestly they aren't as hazardous as some people make them out to be, it is just that unlike combustible hydrocarbons (gasoline, diesel, ethanol) most people don't have much experience and standardized protocols on wtf to do are still being worked out in a lot of places.