Chicago Tribune reporter Adam Sege provides details on 3 people shot and one critically wounded. (Posted on: July 23, 2013)

A 43-year-old man was shot and critically injured during an argument on the Southwest Side late Monday night, and a West Side shooting also left two people hurt, according to authorities.

About 11:40 p.m., someone took out a gun and opened fire during a verbal altercation in the 6300 block of South Rockwell Street, Chicago Police Department News Affairs Officer Hector Alfaro said.

A 43-year-old man was struck in the right side of the back and taken in critical condition to Advocate Christ Medical Center in Oak Lawn, Alfaro said.

The shooting happened in the Marquette Park neighborhood.

In an earlier shooting in the Near West Side neighborhood, two people were hurt when someone in a vehicle opened fire on a group of people standing on the sidewalk about 11:15 p.m. in the 200 block of South Western Avenue, police said.

A 16-year-old boy was struck in the heel and a 47-year-old man was shot in both ankles, Alfaro said. Both were taken to John H. Stroger, Jr. Hospital of Cook County, where their conditions were stabilized.

Police had no suspects in custody in either shooting as detectives investigated.

asege@tribune.com | Twitter: @AdamSege