According to the Forest Park Police Department, a review of security footage showed that the victims seemed to be asleep, seated separately, and did not resist the attack. The shooting occurred in two separate train cars, Xinhua reports.
A suspect has been taken into custody, and a weapon was recovered. The motive is still unknown.
Forest Park is a village in Cook County, Illinois, and a suburb of Chicago.
Also on Labor Day, five people were shot in the afternoon when a suspect discharged a weapon into a crowd along the New York Caribbean Carnival parade route, according to police. Two people were critically wounded.
In Nashville, Tennessee, six people were hurt during a shooting at a bar parking lot early Monday morning.
Over 380 mass shootings have occurred in the United States in 2024 so far, according to the Gun Violence Archive, which defines a mass shooting as an incident in which four or more victims are shot or killed.
MNA/PR