According to the Olmsted County Sheriff's Office, a fire in Oronoco is under investigation. Olmsted County Sheriff's Sergeant Jim Schueller said the fire happened Thursday, around 9 p.m. on the 12000 block of 18th Avenue NW in Oronoco. According to Sergeant Schueller, a driver saw the flames and called law enforcement. Sergeant Schueller said the property owner's 38-year-old son told authorities he was burning downed trees out in the fields and the house caught on fire. Pine Island and Oronoco Fire responded to the call and put out the fire. Sergeant Schueller also said some components of the incident were suspicious. Authorities said both the Minnesota State Fire Marshall and an arson investigator are expected to look at the scene, Friday.