Even before the embers had cooled, investigators determined that
a pyrotechnic device caused the Robbers Fire in Placer County.
But, how do investigators find the source when everything around
it has burned? Robert Moore is an investigator for the
Sacramento Fire Department. He says eyewitnesses provide the
most information, but in really remote areas where no one sees
the fire start, there are still clues to be had. "Any time a
fire moves through an area, not everything is just burned to
pure ash," explains Moore. "There are heavier fuels that survive
more intact than lighter fuels, and those fuels can have
indicators of the direction that fire moved." Moore says once he
follows a fire back to its start, he looks for the source. If
he's lucky, he'll find a burn barrel or a piece of equipment. If
the source of the fire includes an accelerant, the fire may burn
much hotter at the beginning compared to how it burns in
surrounding areas. Moore uses a hand-held hydrocarbon detector
to find out if a foreign substa