Pictures released Sunday showed the extent of damage from inside a warehouse on Indianapolis' southwest side that was gutted by fire on Saturday.
It took firefighters from seven departments eight hours to put out the fire.
But hotspots were still smoldering and could smolder for days.
It could take quite some time for investigators determine what sparked the blaze on Belmont Avenue.
The 440,000-square-foot building housed six businesses.
The fire forced the evacuation of five blocks surrounding the fire.
Four firefighters suffered minor injuries.
Crews expected to remain at the scene for the foreseeable future.
The building housed tires, siding and wooden pallets.