4 people fatally shot on CTA Blue Line train in Forest Park, Illinois; shooter apprehended.

Four people were fatally shot on a CTA Blue Line train in Forest Park, Illinois, around 5:30 a.m. on Monday. Three victims died at the scene, while a fourth succumbed to injuries at a hospital. Authorities apprehended the shooter, describing the incident as isolated, though the motive remains unknown. The victims' identities have not been released, and the investigation is ongoing.