Fire crews battled a large blaze Tuesday night at an R.D. Offutt Co. potato warehouse near Perham. A Perham police officer on the scene said the fire was called in at about 4:20 p.m. Witnesses said the fire originated in the south part of the building and spread north. At least two semi trucks were seen inside the building, engulfed in flames. An unknown amount of potatoes and other contents were also inside.