About 2:56 p.m., the man was confronted by a male assailant in a building in the 1200 block of South Michigan Avenue, according to Chicago police.
The gunman fired multiple shots, striking the man in the leg, police said.
The victim was taken to Northwestern Memorial Hospital in good condition.
Police said the alleged shooter was taken into custody and a weapon was recovered.
South Loop residents tell FOX32 they were stunned to return home to the police investigation.
"Worried, very worried. Just to know that something would happen so close to home is just so concerning," said Cathy Ngoma, who lives just steps away from where the shooting unfolded. "Everybody wants to know that where they live is safe."
Police, on Monday afternoon, focused their investigation on the parking garage located at 1212 S. Michigan Ave.
"We were driving right up to the parking lot and saw it completely blocked off by the police," said Jake Batters, who is visiting from Toronto.
It’s where Batters and friend Alex Slizys planned to park during their trip to Chicago – their first time in the city.
"Had been told that somebody in the building, their car was getting stolen," said Slizys. "The person stealing the car shot the owner in the leg."
Police would not confirm details of the shooting, or the circumstances leading up to it on Monday.
"Just overall really scared, first time in the city and obviously that’s not something you want to hear about as soon as you get here, and it was right when we arrived too," said Slizys.
Charges are pending and detectives continue to investigate.