Well as someone who has been in Morgantown for a few games I can tell you how it happens. The game starts at 730PM. At about 9 or 10 that morning, tents get set up in the hospital parking lot across from the stadium. Once the tents are up, beer starts being consumed. Figure about 8 hours of drinking before game time. Then the team goes and wins. (Oh yeah there is a bit of drinking from illegal flasks in the game too) Now they win, fans are crazy. Get back home. Everyone is still drinking. Someone sees the couch sitting on the front porch. (Don’t ask me why there are couches on the porch...there just are) So they see the couch and decide this would be really cool to have a fire on a cold night like tonight. Lets burn it! Then they either light it in the yard and the fire spreads or they get lucky and it burns out.
There really is no mentality to speak of. I'd imagine that not one of the people who lit fires was sober enough to have a "mentality."
In any case, that was just plain awesome watching WVU dominate VT. VT is over-rated but I think WVU is not given the respect they deserve. They came awfully close to beating Miami in Miami. Hell as a FSU fan, I'll admit it. They played Miami a lot tougher than FSU did.