A Michigan State Police trooper was killed in the line of duty on Wednesday when a vehicle struck him as he was conducting a traffic stop on I-75, authorities said.

Trooper Joel Popp, 39, and other troopers had stopped a suspected impaired driver just after 7 p.m. on a curved part of I-75 near Birch Run, Michigan State Police (MSP) said.

As the troopers were investigating, an 81-year-old male driver struck two patrol cars and Popp, who was standing outside his patrol vehicle.

Popp was rushed to Hurley Medical Center, where he died of his injuries.

INDIANA TROOPER CRITICALLY HURT BY SUSPECTED DRUNK DRIVER WHILE HELPING MOTORIST WITH FLAT TIRE

The 81-year-old driver suffered serious injuries but was expected to survive.

"This is a message none of us wishes to deliver. With a very heavy heart I confirm the death of one of our own, Tpr. Joel Popp," said Col. James F. Grady II, director of the MSP, in a written statement. "I ask that you please keep his family, fellow troopers and all whose lives he has touched in your thoughts."

GEORGIA MAN IMPERSONATING POLICE OFFICER PULLS OUT FAKE BADGE, ATTEMPTS TO ARREST REAL COPS

Popp joined the MSP in January 2020. He is survived by his wife and their young daughter.

He is the 56th Michigan State Trooper to be killed in the line of duty.

Last week, a state trooper in Indiana was helping a motorist change a flat tire on a curved part of I-65 in Indianapolis when a suspected drunk driver struck and critically injured him, Indiana State Police said. Officials said the trooper in this incident, Azariah Keith, is expected to make a full recovery.

Both Michigan and Indiana, along with the other 48 states, have a "Move Over" law which requires drivers to slow down or move to an adjacent lane for emergency vehicles that have their lights flashing or are assisting in emergencies.