A Chippewa County sheriff's deputy is dead after a car hit him near the scene of a semi fire.

The State Patrol says 31-year-old Jason Zunker was setting up cones and flares on southbound Highway 53.

That's when a driver hit Zunker outside his squad car - resulting in head injuries that turned fatal.

The State Patrol says it all started around 9:30 Friday night.

Troopers, along with Chippewa County sheriff's deputies were dispatched to a semi, fully engulfed in flames near Milemarker 109.

"Due to the traffic on 53, with the emergency response out of Tilden, it was decided by the State Patrol officer to close the highway down," said Chippewa County Sheriff James Kowalczyk.

A stretch of Highway 53 at Highway 40 was shut down for hours overnight.

But it was only a matter of minutes before an crash ended Deputy Jason Zunker's assignment.

"Jason Zunker was assigned to detail traffic north of that intersection onto State Highway 40," Kowalczyk said. "And in the process of setting up flares and cones, the officer was struck by a southbound vehicle."

Deputies say 21-year-old Erika Kressin hit Zunker while he was standing outside his squad car in the left lane.

Doctors at Luther Hospital pronounced him dead shortly after Noon.

"We're devastated," Kowalczyk said. "There's not enough words that I can say to the Zunker family to the members of our department, to the deputies that worked hand-in-hand with Jason. This is a loss that will never be replaced."

Zunker had been working for the Chippewa County Sheriff's Department for four years - first, as a reserve deputy patrolling water, snowmobile and ATV trails before being hired full-time.

"Jason was a deputy that always went above and beyond, always had a smile on his face," Kowalczyk said.

Colleagues say the crash is a sad reminder of the dangers of the job.

"It reminds us how difficult it is on these roadways, how all the people play such an important role - both those of us who enforce the laws and those who them themselves," said Lt. Jeff Lorentz, of the Wisconsin State Patrol. "You can't really let down your guard."

Troopers say the driver of the semi and Kressin are both OK.

Troopers say charges are possible, but Kressin is not under arrest. And they say she's a victim in this tragedy as well.

A reconstruction team from the State Patrol has already started what could be a lengthy investigation.