A very serious emergency occurred in the American city of Forest Park (Illinois) .
There was a shooting on the train. At least four people were killed in the incident.
This was reported by MIA "Russia Today" with reference to the ABC News TV channel, which, in turn, refers to police information.
The TV channel notes that local law enforcement officers received an emergency call – they said that three citizens had been shot on the train.
At the scene of the incident, police found three dead people and another seriously injured person.
Three of the victims of the attack died at the scene, and a fourth woman was taken to Loyola University Medical Center in Maywood, where the victim died, ABC News reported.
It further states that law enforcement officers, together with security from the Chicago Transit Authority, tracked down the alleged perpetrator through surveillance cameras.
The perpetrator was detained. He is currently in custody.
According to the information released, city authorities are calling the shooting on the train an isolated incident.
According to officials, the incident does not pose any additional threat to local residents.