4 shot to death on CTA Blue Line train in suburban Chicago, suspect in custody

Four people were shot and killed Monday morning on a Blue Line train in west suburban Forest Park.

Around 5:30 a.m., officers responded to the Forest Park Blue Line station at 711 Desplaines Ave. and found four people shot, Forest Park police said in a press release.

Three of the people died at the scene, while a fourth was taken to the Loyola University Medical Center in Maywood where they later died, police said.

Forest Park police worked with CTA security to put together a description of the suspected shooter, and Chicago police arrested someone matching the description on a Pink Line train where a firearm was also recovered.

"Although this was an isolated incident, this heinous and egregious act of violence should never have occurred, none the less on a public transit train," the CTA said in a statement. "As soon as this matter was reported, CTA immediately deployed resources to assist the Forest Park Police in their investigation into the matter, including review of all possible security camera footage, which proved to be vital in aiding local enforcement."

Blue line service was still suspended from Forest Park to Austin as of 10:30 a.m. as police continue to investigate.

This is a developing story. Check back for updates.