Mike not to jump in here cause i dont have any good input an the arson statue but you stated you had a mech cleaning some tools with a gas rag and it was ignited by a gas appl. or careless smoking. Just want to say that careless smoking could not have been the cause for ignition of gas vapor unless he was lighting his cig at the time. If he was already smoking then you can rule out smoking cause cigs will not ignite gas ( I know sounds crazy but the movies are wrong ) Just some thoughts about the fire.

You know it is crazy how many fire investigators right now are saying i am full of shit cause they think a cig will set gas off. Well go try it for yourself dont feel bad i had to haul a whole class in Ky outside in the parking lot and let them go by in single file and put their cigs out in a pan of gas before they would get the hint. Amazing what the movies will have you believe.

Gary L. Haun jr. CFI/CFEI/CFII/CVFI/VA-CFI