Investigators have a theory as to how the fire at Bourdeau Brothers in Canton started.
According to Michael LeCuyer, St. Lawrence County's director of emergency management, they are thinking vapors from weed killer sprayed around the building may have gotten into the walls and spontaneously ignited because of Tuesday's heat.
That's not a final determination though.
An official report could come Friday.
The fire damaged one building, but the business reopened the next day.