CHICAGO (CBS)– For the second time in three days, an Illinois State Police trooper was fatally struck.

ISP Acting Director Brendan Kelly addressed the media Saturday, hours after Trooper Gerald Ellis, 36, was fatally struck on I-94.

Kelly said Ellis, was on-duty in his squad car traveling home on I-94 westbound near milepost 16.75 in Green Oaks, when a wrong-way driver, who was traveling eastbound in the westbound lanes, struck Ellis head on.

Ellis was transported to Advocate Condell Medical Center and was pronounced dead just after 4 a.m

The fallen trooper was an 11-year veteran of the ISP District 15 in Downers Grove. Kelly said Ellis leaves behind his wife and two children.

Exactly what happened in the moments before Ellis’ death is still being investigated, but Kelly is calling Ellis a hero.

“By doing what he did today, he saved lives,” Kelly said.

The wrong-way driver, and sole occupant of the other vehicle, was also pronounced dead, according to Kelly. The driver’s identity has not been released yet.

Kelly said the investigation is ongoing.

Trooper Brooke Jones-Story was struck Thursday by a truck tractor semi-trailer combination while outside her squad car inspecting another semi, Illinois State Police said. She was a 12-year veteran of the Illinois State Police District 16 in Pecatonica.

“The Illinois State Police are now mourning the loss of a sister and a brother,” Kelly said.

In January, Trooper Christopher Lambert was hit by a driver on I-294 while assisting at the scene of an accident.

Their deaths have sparked a renewed push to remind drivers of Scott’s Law, the “Move Over” Law, which requires people to slow down and avoid first responders when they see emergency lights.

Not since 1997, Kelly said, has the Illinois State Police lost two troopers in three days. It has been 66 years since the ISP has lost three troopers in a single year and Kelly reminded, “It is still on March.”

Illinois Secretary of State Jesse White put out a call to action Saturday afternoon, telling motorists to stop driving while distracted, impaired or texting.