Why did these cars burn way out by them selves?

How did the fire get that hot? Don't say the gas. I've seen cars wreck violently and explode and not burn this bad.

The Airborne Laser, ABL, uses a high energy Chemical Oxygen Iodine Laser (COIL) on a modified Boeing 747-400F aircraft to detect, track and destroy any class of ballistic missiles in their boost stages of flight.

https://tinyurl.com/yq39bzss - YAL-1 Airborne Laser Testbed