How much methane was built up in there? Doesn't anyone know they are supposed to empty those things from time to time?
ewwwwww......
Gives a whole new meaning to... "that BURNING sensation"!!!!
This sounds like a recurring urban myth to me. The porta potties are vented thru their roofs. This oldie was explored on myth busters in regards to regular toilets and proved impossible.
Just tossing a lit butt in the gas would not ignite it. They had to use a lit match to make it go off. Either a weak brained investigator using an urban myth to spice up a slow news day or an anti smoking nazi on a jag.