Lieutenant Gillen and members of his truck company were dispatched to the site of a motor vehicle collision on an expressway to provide a traffic shield with their apparatus and to assist ambulance personnel. Two state police cars were positioned behind the ladder truck in a further attempt to divert traffic.
As the incident was being concluded, Lieutenant Gillen walked around the truck to make sure that everything was ready to go. As Lieutenant Gillen walked, a passenger car ran over a line of flares in an attempt to slip by traffic. The car then struck a tractor trailer, spun, and pinned Lieutenant Gillen between the car and the ladder truck.
Lieutenant Gillen was treated at the scene and then airlifted to the hospital. His legs were crushed in the collision, and he had lost a substantial amount of blood. He died 10 hours later.
The driver of the car that struck Lieutenant Gillen was under the influence of alcohol and was driving on a suspended driver’s license. He was later charged with reckless homicide. There were no injuries in the original collision. Lieutenant Gillen had been promoted to lieutenant just two weeks prior to his death.
The Chicago fire commissioner was quoted as saying "I have a hard time calling this an accident, this was a crime, an absolute crime."