Union Pacific spokesman Aaron Hunt said the person was "a pedestrian trespasser" who was sitting on the track.
"The incident is being investigated as a possible suicide," Hunt wrote in an email to The Times. "Our hearts and thoughts go out to the family and friends of the individual."
No additional information about the deceased was immediately available from Los Angeles police, the Fire Department or the Los Angeles County coroner's office.
Union Pacific tracks were shut down after the incident, which occurred about 3 p.m., according to
Metro spokesman Dave Sotero said Blue Line service was continuing.