4 sleeping passengers shot, killed on CTA Blue Line in Forest Park, suspect in custody  Chicago Sun-Times4 people shot to death while sleeping on CTA Blue Line train in Forest Park, mayor says  ABC7 Chicago4 people were killed on a train in the Chicago area on Labor Day, police say  NPR4 killed on train in Chicago-area appeared asleep before shootings, police say  NBC NewsCTA Blue Line shooting: Four dead after being shot while sleeping, mayor says  WGN TV Chicago