OAKFIELD, Wis. (CBS 58) -- A two-vehicle crash on U.S. Highway 151 resulted in the death of a Sun Prairie woman and serious injuries to a Waupun man, according to the Fond du Lac County Sheriff’s Office.

Deputies said the crash happened on Tuesday, July 22 at 12:27 p.m. near Thill Road in the Town of Oakfield.

Officials believe 81-year-old Mary Naggatz may have suffered a medical emergency while driving southbound, causing her vehicle to cross the median and crash into a northbound vehicle driven by 58-year-old Daniel Sturm. A third vehicle was sideswiped but its occupants were uninjured.

Two Dane County sheriff’s deputies saw the collision and attempted to render aid.

Naggatz was pronounced dead at the scene. Sturm was taken to St. Agnes Hospital to treat serious injuries.

Anyone with information is asked to contact the Fond du Lac County Sheriff’s Office.