CHICAGO (CBS)--An overnight attempted carjacking and fatal shooting in the South Loop snarled traffic in downtown Chicago Friday, as investigators cleared the scene.

A 22-year-old man was fatally shot by a 41-year-old driver of a BMW the younger man tried to carjack around 3:15 a.m. in the first block of Ida B. Wells Drive, police said.

The incident began when the 22-year-old rear-ended the BMW in a Volkswagen he was driving. The driver of the BMW got out to inspect the damage when the 22-year-old pulled out a handgun and demanded the keys.

Recent Car Thefts In South Loop

The driver of the BMW, a concealed carry license holder, got his gun and shot the would-be carjacker in the head.

The 41-year-old driver is being questioned by police.

Road closures that affected the area early Friday had ended by the afternoon, police said.

A woman, who asked to remain anonymous, said the Volkswagen is hers and was stolen from her son around 1:30 a.m. Friday when he was filling up at a gas station at Congress and Kostner. She only bought the car about a month ago.

The Volkswagen was eventually located by police at the crime scene about two hours later.

Police are reviewing the fatal shooting and the car’s owner, who is a cancer patient and depends on the car for transportation to appointments and treatment, is in the process of trying to get her stolen car back.