Dunn County investigators say a man killed last week was changing a tire on a farm wagon when it exploded. The tire was being inflated when it and the attached metal rim hit 20-year-old Seth Splitter of rural Elk Mound in the head. Splitter was dead at the scene. He had been working on a wagon which is used to haul silage. The sheriff’s office is investigating to see what caused the tire to explode.