The car interior was completely gutted. The dash had melted and the seat, no doubt nonflammable, had caught fire and was ashes.
This all happened from a little tiny cell phone battery. Multiply the energy storage of this battery x 1000, 10,000 (a guess) and you have Chernobyl. And how do you disconnect the power from the batteries since the power is fed within the house? There isn't an onoff switch that is easily accessible. Not like you can cut the power from it if it is in runaway. There is probably a switch on the outside of the house somewhere.
We’ve learned to mitigate the explosive risks of natural gas, and accept the rare kaboom for cost/convenience benefits. Likewise have to implement safety features for large battery installations.