The crash happened on Wednesday at about 6 p.m. near Broadway Street in Blue Island, CSX officials said.
CSX said one person died in the crash and another was taken to an area hospital in critical condition.
The medical examiner identified the victim as Jair Ortega, 19 of Harvey.
"CSX extends its deepest sympathies to everyone impacted by this tragic incident and will continue to support local law enforcement as they complete the investigation," a CSX spokesperson said.