Thousands of GO Transit riders were stranded aboard trains for several hours after a person was fatally struck on the Barrie line.
The incident occurred on the track near Castlefield Avenue at around 8:55 a.m.
Metrolinx estimated that 3,000 to 5,000 passengers were stranded on three trains on the line, including the one which struck the pedestrian.
The investigation was wrapped up at around 12:30 p.m.