Investigators say a commercial fire in Emmett earlier this week started accidentally.
The fire broke out Monday morning at Sonbyrd Industries.
Evidence shows a saw blade from a machine came loose which caused sparks to ignite sawdust.
Workers opened the dust collection system, causing an explosion.
Two employees were seriously injured and taken to a burn unit in Salt Lake City.
The fire completely destroyed the building.
Fire at Sonbyrd Industries in Emmett