MARATHON COUNTY, Wis. (WTAQ) - A man was killed after his van started on fire west of Wausau early Sunday. Marathon County authorities said 38-year-old Jason Sandberg was sleeping in the vehicle with an electric space heater running. The blaze happened in a driveway outside a home in the town of Rib Mountain, and the heater was using an extension cord connected inside the house. Sheriff’s deputies are still investigating.