One of the videos viewed on Montreal TV showed a trailer for selling food (a "chip wagon") being removed from the tunnel. It was reported that this trailer was being towed by the RV and may account for some of the wild numbers published on the quantities of propane that were bandied about because it had two large tanks of propane attached to it. The trailer itself appeared undamaged. No explosion caused by propane was reported locally though.
There has been nothing reported that indicates the real initial cause of the fire, only speculation so far. It burned so badly simply because getting firefighting equipment and crews to the site was very difficult. Firefighters may also have been held back due to the reported presence of propane and threat of a possible explosion.
I don't ever recall seeing signs before that particular tunnel regarding shutting off propane but I seldom use it and never with an RV... but this RV may have had his fridge on, as many do, while traveling.
