Three people were shot Monday in Chicago, including a homeless man killed in an encampment along an expressway in the South Loop.

The shooting happened about 4:45 p.m. at a “grassy embankment” in the 1000 block of South Des Plaines Avenue, Illinois State Police said in a statement.

When investigators arrived, they learned the Douglas Robinson, 57, was shot following an argument with another homeless male who also lived in the area, state police and the Cook County medical examiner’s office said.

Robinson suffered a single gunshot wound and was rushed to Stroger Hospital, where he died, authorities said. A person of interest was arrested.

Anyone with information about the shooting should call state police at (847) 294-4400. Tipsters can remain anonymous.

In nonfatal shootings, a man suffered gunshot wounds to both his legs during a drive-by shooting Monday night in the Calumet Heights neighborhood on the South Side.

The 26-year-old was walking about 10:10 p.m. in the 9000 block of South Dante when shots were fired from a passing black vehicle, police said.

He was struck in both legs and taken to University of Chicago Medical Center, where his condition was stabilized, police said. Area South detectives are investigating the shooting.

Earlier in the afternoon, an 18-year-old man crashed his car after being shot in the Brighton Park neighborhood on the Southwest Side.

The teen was sitting in his car about 2:30 p.m. in the 4100 block of West 43rd Street when a dark-colored vehicle pulled up behind him, according to police. When the man drove off, the driver of the other vehicle followed him before pulling up alongside his car.

Someone inside the other vehicle then fired shots, striking the man in the hand and causing him to crash into a parked vehicle, police said. He was taken to Mount Sinai Hospital in good condition.

Area Central detectives at investigating the shooting.