Officers responded around 3:30 p.m. Thursday to the area near Forest Preserve Drive and Addison, where two men were found with multiple gunshot wounds behind a home on West Cahill Terrace. One of the victims, a 20-year-old, also suffered a gunshot wound to the head, according to police.
Both people were taken to Lutheran General Hospital in critical condition, where they later died.
Residents in the area said the shooting followed a heated exchange outside. Andy Jekiel, who lives nearby, described what he heard.
"It was like the Wild Wild West. They shot each other," Jekiel said.
Jekiel said he first heard raised voices before the gunfire erupted.
"They were shouting at one another," he said.
"It was an argument going on. We heard something going off. Then all of a sudden, pop, pop, pop, pop. I thought it was fireworks."
Crime scene tape surrounded several apartment buildings for hours as investigators worked the scene.
Jekiel also said he heard there may have been multiple weapons involved.
"I think there were three guns laying down on the floor from what I understand," he said.
Authorities have not confirmed whether any firearms were recovered at the scene, nor have they identified a motive. Police also said they have no information to share about a possible suspect.
Neighbors expressed shock over the violence.
"Over an argument. They can't come back. They're gone. Life is so precious. It's sad. To be honest with you, it's terrible," Jekiel said.
The investigation remains ongoing.
INTERACTIVE SAFETY TRACKER Track crime and safety in your neighborhood