A Janesville man was struck by a semitrailer on Interstate 39/90 north of Janesville on Monday morning, according to the Milton Fire Department.
Deputy Chief Pete Mory told News 3 firefighters were called to northbound lanes of I-39/90 in the area of County Road M at 9:31 a.m. for a report of a pedestrian who was hit by a vehicle.
Dennis R. Bell, 46, crashed into the guardrail, causing his 2013 Honda Civic to leave the roadway, officials said. Bell got out of his vehicle, walked into the lane of traffic on I-39 and was hit by a semitrailer.
"A single patient, we packaged him and turned the care over to the paramedics," Mory said.
Bell was taken to Mercy Hospital and Trauma Center in Janesville with life-threatening injuries. The driver of the semitrailer, Mark E. Nesson, 35, from Sun Prairie, was not injured.
Officials said it is unclear what caused the initial accident involving Bell's car, but the investigation is ongoing.
Northbound traffic on the interstate was tied up for more than three hours after the crash.