A house fire turned deadly Friday in rural Polk County, according to authorities. The Polk County Sheriff’s Office said firefighters extinguishing a blaze in the 2400 block of 90th Street in the town of Bone Lake discovered a body inside the home. Crews responded to the scene -- located near Luck -- after receiving a report at 8:54 a.m. of a structure fire there. Authorities did not release the victim’s name pending positive identification and family notification. The remains were sent to the Midwest Medical Examiner’s Office in Anoka, Minn. The incident is under investigation by Polk County investigators, the State Fire Marshal’s Office and the Polk County Medical Examiner’s Office.