After two days of intense investigation, the Bureau of Alcohol, Tobacco, Firearms and Explosives has determined that a fire that gutted the Challis office of the U.S. Bureau of Land Management was “not a criminal act,” and found no evidence of arson. “The cause of the fire was ruled undetermined, with no evidence of any criminal act,” the ATF said in a news release. “Investigators cannot conclusively determine the cause of the fire, but have no evidence of an added accelerant in the BLM field office fire.”

The fire started in a shop area and was reported during the early morning hours Tuesday; the office building was a total loss. ATF investigators “methodically removed the debris from the heavily damaged structure,” and “took photographs, recovered fire debris from the scene for analysis, and conducted numerous interviews.”

No injuries were reported in the fire, but damage to the office and its contents has not yet been estimated. Twenty-five federal employees worked in the office.

The ATF is the federal agency with jurisdiction for investigating fires and crimes of arson.