The event was doubly unfortunate because of the missing metal guard rail on the right (damaged in the accident a day earlier). The car hit metal posts, which destroyed the battery pack and "immediately set the car into flames." With the guard rail support, it would not have ended that badly, we guess. The Tesla Mex wrote:
"While driving southbound on I 65 in West Lafayette Indiana on October 15th at approximately 5 AM my car hydroplaned while in auto pilot hitting the left median cement barrier with my front driver side bumper then sliding to the side of the road, but the day before that, their was an accident where a tractor trailer took out the metal guard rail.
So when I slid to the side of the highway shoulder, the exposed metal posts from the missing metal guard rail from the day before accident, made me slid across the grass shoulder which made me hit my undercarriage across one of the metal posts and it opened up my battery pack underneath the vehicle which immediately set the car into flames.
If the guard rail would have been there I just would’ve smashed up my passenger side door and my Tesla would have been completely fine except for the smash door and the front scraped on the front driver side bumper."
What we see in the video is a full-blown battery fire, with 2170-type cylindrical battery cells popping out in various directions.
Firefighters tried to put down the fire with water, but we know how difficult it is to distinguish a battery fire, even with some help from the rain - "The car kept lighting back up!"
Fortunately for the driver, he was ok, and even kept his sense of humour saying "I'm pretty sure that's gonna be a total loss."
At some point, an excavator came into action to flip the car upside down and tear down the battery pack for easier access for water to put out the fire and finally cool the batteries down so they would not reignite.
It's amazing that at this point the hazard lights were still working.
Once the fire was put out - firefighters double checked the temperatures using a thermal camera. It's really a lot of work to put out a battery fire.
Below is the same event in three separate videos: