Recently, my wife and I were driving to California for a short vacation. Somewhere between Phoenix and the California border, we came to an emergency slowdown sign. The cause of this emergency was a tractor-trailer that had caught fire. It was something I dont think I had ever seen.
The tractor unit was burned down to the frame. The engine was not visible in the wreckage, even though the cab body was gone! I realize that most tractor bodies are now fiberglass, so it would have burned out. The trailer was still in place, hooked to the fifth wheel, and appeared undamaged.