Authorities say a semi driver suffered a heart attack prior to plowing his trailer into five parked vehicles and crashing into a truck stop Saturday.
Fifty-year-old Douglas Shepard of Hazelton, Iowa died later at an area hospital.
The Dane County Sheriff's Office says the trailer was headed south on Highway 51 when it veered into a ditch on the right side of the road, careening through a parking lot until it smashed into the TA Travel Center in the Town of Burke.
An 11-year-old male relative who was with him suffered minor injuries.
An 18-year-old Merril woman in one of the five vehicles hit suffered minor injuries.