RIPON, WI (WTAQ)- Police Chief Dave Lukoski says the cause of Wednesday morning's blaze is still being investigated -- but federal, state, and local officers could find no evidence of arson. He said a number of accidental causes are not being ruled out. Fire Chief Tim Saul said it's been hard to investigate, because large amounts of ice are coating the structures. He said the stability of the old buildings is a concern, and walls are being taken down one piece at a time. The fire destroyed three buildings that contained businesses and apartments. About two dozen tenants were displaced.