(Colfax, ND) — Five people were injured in a chain-reaction crash near Colfax Saturday night. Authorities say it began when an ambulance caught fire on I-29, and the interstate was shut down so fire crews could extinguish the flames. A short time later, a car crashed into stopped traffic on the interstate, damaging a total of four vehicles. One person suffered life-threatening injuries, and the driver who crashed into the stopped traffic was arrested on DUI charges.