The person was struck between Dee Road and Park Ridge stations during the middle of Tuesday evening's commute. He or she was killed, officials said.
Union Pacific / Northwest train No. 631 was en route to McHenry when it hit a pedestrian near the Touhy Avenue overpass, just northwest of the Uptown Park Ridge station, according to Park Ridge police Cmdr. Jason Leavitt.
As of 7:45 p.m., all trains between Crystal Lake, Harvard and Chicago are still stopped following the 5 p.m. incident, Metra spokeswoman Meg Reile said.
The Cook County Medical Examiner's office confirmed the person struck by the train was killed, but the gender and age of the individual were not yet known.
Metra officials are urging commuters to find other means of transportation, as trains on the Union-Pacific / Northwest Line could be delayed between two and three hours as the investigation continues, Metra's website said.
For the latest delays and travel information, visit Metra's website.
The Sun-Times Media Wire contributed to this report.