Police had no explanation for a series of 13 accidents that brought I-15 to a near standstill in both directions in north Utah County Friday night.
Weather conditions were reportedly good at the time of the accidents. Police said road debris and following too close appeared to be the primary elements causing the crashes.
The accidents, which occurred over a two-hour span between 6 p.m. and 8 p.m., sent at least four victims to area hospitals with minor injuries, the Utah Highway Patrol said.
Three of the multiple-vehicle accidents between Orem and Point of the Mountain resulted in injuries. The Utah County Sheriff's Office sent two ambulances to the crashes, police said. Two of the injury accidents were in the northbound lanes in Lehi, one involving four vehicles. The third injury crash was in the southbound lanes, police said.
In all, the crashes damaged 22 vehicles, including one semi trailer truck.
Five of the accidents were the result of vehicles hitting a tire in the roadway. Police said they had not determined how the tire got onto the road. The other accidents were simply the result of inattentive driving and following too closely, police said.