GO Transit service along the Stouffville line is experiencing significant delays after a person was struck by a train near Centennial GO in Markham.According to the transit agency, the area is now under the control of emergency personnel, and trains can’t pass through until an investigation is complete.The incident occurred just south of Centennial GO.GO Transit said the Old Elm GO train departing at 9:08 a.m. has been cancelled. Riders are being told to board the next train from Unionville GO at 10:39 a.m. that will make all stops to Union Station.More to come