Illinois state trooper fatally struck on roadside during highway traffic stop

An Illinois state trooper died in the line of duty on Thursday when a semitrailer slammed into her during a highway traffic stop.

Brooke Jones-Story, 34, was on the shoulder of U.S. Highway 20 in northern Illinois at around 12:20 p.m. when a semitrailer veered off the roadway, striking the officer, her squad car and the commercial tractor-trailer she was inspecting at the time, state police said.

The impact of the crash caused both trucks to burst into flames, covering the surrounding area with thick clouds of dark gray smoke, according to social media video.

Brendan Kelly, acting director of Illinois State Police, said she was a 12-year veteran of the force and the wife of a retired Illinois State Police officer. He described her death as "tragic and untimely."

"Today, trooper Jones-Story paid the ultimate sacrifice while protecting and serving the citizens of Illinois," Kelly said at a press conference Thursday. "The men and women of this department -- especially the troopers and colleagues of trooper Jones-Story -- are sad, hurting and they're angry."

"These troopers are just doing their jobs and trying to protect everyone. How many times does this have to happen? How many more have to be hurt or killed?" he asked, noting the uptick in similar officer-involved crashes over the last few months.

The unidentified driver who hit Jones-Story was cited with a violation of Scott’s Law, which mandates that drivers must use caution around emergency vehicles, and improper lane usage. The investigation remains ongoing.

At least 15 troopers have been involved in similar roadside crashes throughout the state this year, according to Kelly. Another state trooper was hit and killed outside his squad car in January.

“When is enough enough?” Kelly said Thursday. “When are more people going to start giving a damn and doing the right thing?”

Jones-Story's death comes just days after Illinois Gov. J.B. Pritzker vowed to strengthen efforts to enforce Scott's Law.

"Our state troopers do incredible work keeping the public safe, and it is devastating to the entire state that another has been killed on the side of a highway," Pritzker said in a statement. "I cannot stress strongly enough -- when you see an emergency vehicle on the side of the road, change lanes or slow down. It’s the law, and it’s the only decent thing to do."

Jones-Story leaves behind her husband, her parents, two step-children, a step-grandchild, a sister and her farm animals and dogs "who she loved dearly," Kelly said.

State police mourned the fallen officer with a highway procession near the scene of the crash on Thursday.

Highway officials also displayed a special overhead message on roadways in the wake of the tragedy: ENOUGH IS ENOUGH SCOTT'S LAW = MOVE OVER SLOW DOWN.

ABC News' Darren Reynolds contributed to this report.