Causal or contributing factors not yet known, but it looks like it included and the likely source was the high-voltage battery. It looks like it may have spontaneously combusted without an accident. This could possibly verify there is possible design, manufacturing, and or quality control issues with Tesla batteries. This may support claims by whistleblowers that there are manufacturing and quality control issues related to Tesla batteries.
Tesla Model S engulfed in fire in Poland
The Volunteer Fire Brigade of Wałbrzych, Poland, posted an image on Monday of four firefighters trying to extinguish a blaze that erupted from a Tesla Model S vehicle in Boguszów-Gorce town.