DULUTH, MN (KDAL) - Fire on the second floor of an up and down duplex caused about 20 thousand dollars worth of damage early Sunday morning at 320 North 27th Avenue West in Duluth. Firefighters found smoke coming from multiple windows on the upper floor of the structure when they arrived. The upstairs occupant had evacuated after attempting to douse the flames with a fire extinguisher. A limited mobility occupant in the lower floor was assisted out by Duluth Police as firefighters battled the blaze upstairs. The cause of the fire is under investigation by the Duluth Fire Marshal's Office.