SIOUX FALLS, S.D. (KELO) — A Harrisburg couple has been identified in a deadly crash south of town over the weekend. Authorities say a pickup was heading south just after 10 a.m. Saturday morning. At the same time a car was heading east and went into an intersection after stopping at a stop sign. The car collided with the pickup and both went into the ditch. The driver and passenger in the car, 79-year-olds Arnold and Rita Ardell Topf, died at the scene.The driver of the pickup was not hurt.