ScotRail has announced that two people have been struck by separate trains within two hours.
Emergency services were called to Kilpatrick railway station, in West Dumbartonshire, at around 3pm on Thursday following reports of a casualty on the tracks.
A person, who has not yet been identified, was pronounced dead at the scene.
Following the incident, both lines between Dumbarton Central and Dalmuir have been closed.
It is the second incident to cause train disruption on Thursday, after a person was fatally struck at Bishopbriggs railway station at around 1.18pm.
Following the incident, services leaving from Queen Street station will be subject to delays.
ScotRail said: “Unfortunately we have had reports of a person being struck by a train between Dalmuir and Dumbarton.
“We are working closely with emergency services during this time and will keep you updated. Both lines are closed at this time.”
A British Transport Police spokesperson said: “Officers were called to the line near Kilpatrick station at 3pm on 25 May to reports of a casualty on the tracks.
Paramedics also attended, and sadly a person was pronounced dead at the scene.
This incident is not being treated as suspicious and a file will be prepared for the procurator fiscal.”