Police say Frank Caruso of Oak Brook died of his injuries early Saturday.
The trooper was helping with a crash near Mill Road when another vehicle smashed into his squad car. Caruso was in the back of the trooper's vehicle and died in the second crash. The two had been waiting for a tow truck to arrive.
Another driver witnessed the crash and pulled over to help.
"It's a shame, too, a simple mistake of a person, a small mistake of a person...changes lives," said witness Shameet Patel.
Crews took the trooper to the hospital with a possible concussion.
Daniel C. Clark, 32, of Chicago, was charged with aggravated DUI for allegedly crashing his vehicle into the trooper's car. He was hospitalized with non-life-threatening injuries.
The cause of the crash is under investigation.
Clark was scheduled to appear in bond court Sunday.
The Associated Press contributed to this report.