A 36-year-old man was inside a gas station in the 7600-block of South Halsted Street in Gresham just before 11:15 a.m., when a 38-year-old and a 20-year-old man entered, police said.
Both men pulled the 36-year-old by his hair, according to CPD.
The man then pulled out a knife, and stabbed the 38-year-old in the neck, police said.
The 20-year-old pulled out a gun, and hit the 36-year-old in the face, police said.
SEE ALSO: Youth mentor shot to death at Near North Side block club party was trying to change lives, mom says
The 36-year-old fled, and both suspects also left the gas station, and were taken into custody by responding officers.
The 38-year-old was taken to University of Chicago Medical Center, where he died.
The 36-year-old was taken to U of C in fair condition.
No one else was injured, and a gun was recovered on the scene, police said.
CPD initially reported the incident as an attempted robbery. It was not immediately clear what led up to the altercation.
Area Two Detectives are investigating.
INTERACTIVE SAFETY TRACKER | Track crime and safety in your neighborhood