wrote in message

stuff snipped

There is a difference between Natural Gas and Propane. With propane
being heavier than air a basement gas leak can go undetected,
smell-wise - and still explode. NG is a bit different - being lighter
than air the smell gets around a lot faster.

If the gas is leaking in the basement of an enclosed house, it would
probably escape through the attic vents or the chimney and be dispersed high
above the ground. Then, since it's lighter than air it would rise up. A
whole house could fill with gas without anyone at ground level having any
idea there was a leak.

While there's a whole lot of circumstantial evidence here, it's going to be
very hard to prove arson beyond a reasonable doubt short of toolmarks and
fingerprints on the tools that made those marks.

--
Bobby G.