An Arlington Heights man who died Thursday morning on the train tracks at the Belmont station in the North Side Lake View neighborhood has been identified.

Trains were halted at Belmont because of an unauthorized person on the tracks, according to a service alert issued by the CTA. Later updates referred to the incident as a medical emergency on the tracks.

CTA spokeswoman Irene Ferradaz said preliminary information indicated that power was shut off in both directions about 10:15 a.m. because of a person on the tracks at Belmont, but that the person did not make contact with a train or the electrified third rail. She said Chicago Fire Department crews removed the person from the tracks.

CFD spokesman Larry Merritt said the person died, but did not provide further information.

On Friday morning, the person was identified as 31-year-old Patrick J. O’Brien, according to the Cook County Medical Examiner’s Office. He was pronounced dead at 10:36 a.m.

An autopsy Friday did not rule on the cause and manner of O’Brien’s death pending further investigation, the medical examiner’s office said.