The STM announced via the ligne orange Twitter account that the entire line has been shut down due to the presence of smoke. The affected stations were initially between Beaubien and the Laval terminus of Montmorency, but the STM has since extended the shutdown to the other terminus at Côte-Vertu. There are no other details. It is unclear where the smoke was first detected. This is the second major metro service interruption in one day and comes after a difficult week for the STM.
UPDATE: Service is resuming on the orange line.
Last week, a water main break resulted in flooding at Square Victoria-OACI station and the complete shutdown of the downtown portion of the orange line between the busy Lionel-Groulx and Berri-UQAM stations.
The STM shrunk the extent of the shutdown twice before finally resuming service.
Service is now resuming on the orange line.
We will update this article with more information as it becomes available.