The four-alarm fire last week that destroyed the historic Butternut building in downtown Omaha is being ruled an accident. That was the word Friday from Bureau of Alcohol, Tobacco and Firearms investigators.
The ATF says the fire probably started after some sparks from a construction grinder landed on flammable material. They say the fire started in the southwest corner of the building between the top ninth-floor and the roof.
Investigators say the fire may have smoldered for as much as two hours before the big blaze started that eventually gutted the landmark building.
The Butternut building was being renovated into up-scale living units and office space. Authorities estimate loss at about $30 million.
Investigators say they were able to make their determination after interviewing more than 200 witnesses, and by looking closely at videotape gathered during a helicopter fly-over of the building Wednesday.
The ATF was called in to assist in the investigation due to the significant loss.