A friend and I were driving a Uhaul down to Arizona and we got onto I40 west in New Mexico. Traffic was backed up due to an RV -looked like a diesel pusher with Jeep Wrangler in tow that had caught fire. The front was burned and both front tires were flat. RV looked ok. Fire was out when we passed it. Just curious as to what may have caused it since I pull a vehicle in tow. Blown tire?