An overnight derailment near Downsview station has shut down service on the northern end of the Spadina subway. CablePulse 24 reports that shuttle buses are ferrying passengers between the stations north of Lawrence West.

The accident occurred when a work train developed coupler problems, separating the cars and causing them to leave the tracks, spilling the rails in the tunnel. Work crews are on the scene and the TTC reports that normal service should resume shortly.

(Update: Monday, March 13 at 9:17 a.m.): This story in the Globe and Mail gives more details of the accident. Although it doesn’t state where the derailment occurred, the stations north of Lawrence West were shut down until noon before service resumed.

The TTC is examining the cause of the accident, but does not believe any problems exist with the couplers holding together the passenger trains.