An argument that escalated into violence has claimed the lives of two young men.

According to WGN9, the altercation began around 3:20 a.m. Thursday inside an apartment in Chicago’s South Shore neighborhood. Authorities say that at one point during the argument, the two men each displayed fire arms and opened fire on one another. It’s unclear what sparked the altercation.

Officials have yet to release the names of the victims, but confirmed one of them was an 18-year-old man who sustained gunshot wounds to the face and stomach. He was pronounced dead shortly after he was transported to the University of Chicago Medical Center.

The second victim was a 24-year-old man who was pronounced dead at the scene. The outlet reports he had suffered multiple gunshot wounds to the chest, shoulder, hand, and leg. 

Authorities say they recovered two handguns from the scene. Investigators have yet to provide details about the men’s relationship but described the deadly shooting as a domestic incident.