Police in rural Wisconsin are trying to piece together what prompted a deadly stabbing spree Saturday among people tubing on the Apple River. A 17-year-old male from Minnesota was killed and four other young adults wounded in the attack in Somerset, reports KARE11. Police arrested a 52-year-old Minnesota man following the afternoon assault. "Thank goodness a witness had taken a photo of him," St. Croix County Sheriff Scott Knudson told reporters, per the Minneapolis Star Tribune. "Another witness located him at the exit of the tubing area, where he was taken into custody."
Police have not spoken about a motive. "We don't know yet who was connected to who, who knew each other, or what precipitated it," says Knudson. "It's a tragic day." The stabbings took place at a relatively inaccessible spot on the river, and deputies had to wade through waist-deep water to reach the victims, per the New York Times. Other tubers helped them treat the injured, believed to be in their 20s. The river is a popular locale for residents of the Twin Cities, with companies offering tubing outings with shuttles. (Read more Wisconsin stories.)