four passengers on an L train are dead and a suspect under arrest after a mass shooting spanning two train cars in a Chicago suburb police say the shooting happened on a blue train Blue Line train that was heading from Chicago's O'Hare Airport to the suburb of Forest Park three of the victims died on the train another was taken to a nearby hospital where they later died the shooting so far police say appears to be random and that there is no known motive it's a horrible situation you know it's definitely something that you don't want to wake up to you know it's a Monday morning on a holiday police are not yet releasing the names or ages of the victims investigators say surveillance video LED them to the suspect who was on a different train