I watch a couple of USFS Rangers down on their hands and knees on the side of a Freeway until they found a white ash remains of cigarette. The another fire they found a paper match folder set up to ignite when a match stuck in the side lite the rest. All that was left was ash but is was enough. Since the “Station Fire” was right up the road from
a USFS Fire Station the first crew there had a pretty good idea where the source started. A series of 4th of July sparklers thrown from a PU Truck started a half mile long string of fire. They found all 12 of the sparklers.
I didn’t mean to say that the “Station Fire” was started by sparklers. I was trying to show another case of arson fire
where alot of work found the sources.