We've always had a fire extinguisher in our trailers for the thought of something like this happening. But after seeing this and thinking that there might be a chance a car was in there, I'd think about adding a good set of shears to cut the straps off a car in a hurry instead of crawling on the ground to unhook it. Good thing it was onthe way home and not to the show.
Glad you and your truck are okay.