"There won't be any fines," said Chuck Arnold, chief ranger for the Catoosa-Whitfield District of the Georgia Forestry Commission.
Investigators heard several accounts of how the fire started but finally determined the blaze began when a contractor working near a house threw down a flaming chain saw.
"He threw the chain saw, because he didn't want to burn himself," Arnold said.
"I've got one just like it," added Arnold, whose chain saw sports scorch marks because "the housing's too close to the muffler."
The contractor inadvertently made things worse by using an excavator to dump dirt on top of the blaze, Arnold said. Instead of smothering embers, that blew them around.
"By trying to put it out, it spread it everywhere," Arnold said.
The fire started near a home on eight acres on Cherokee Valley Road owned by Michael Gonzalez. He hired the contractor to clean up trees.
"I'm relieved that I'm not going to get any big fines," said Gonzalez, who added that he "bit his tongue" when a fire investigator initially approached him and said, "I'm not here to arrest you -- yet."
"I didn't do anything," Gonzalez said Tuesday. "All I did was hire this [contractor] to cut trees."
In unrelated fire news, Arnold said an arsonist set six separate fires on March 11 on Houston Valley Road that burned 15 acres. Arson investigators have sent material from the scene to a crime lab for analysis, he said.