Unexpected incidents have led to significant construction delays for Montreal's most anticipated public transit project, the Réseau Express Métropolitain's (REM).\nFirst, an "unexpected detonation of a century-old explosive charge" in the Mount Royal Tunnel, along with the separate discovery of structural degradation in some tunnels walls, has led officials to push the opening of the segment between the Gare Centrale and Du Ruisseau stations by over a year, to fall 2023.\nThe surprise detonation occurred on July 20 and thankfully, no one was hurt.\nEditor's Choice: Red-Zoners Reportedly Swarmed The Laurentians This Weekend To Get Some Orange Zone Freedom\n\n\n“\n\n\nWhile the pandemic is still ongoing, the project office continues to closely monitor the situation with relevant authorities.\n\n\nRéseau Express Métropolitain (REM)\n\n\n\nTunnel work will also affect "opening the West Island, Deux-Montagnes and Airport branches, since the tunnel lies in the central segment," the REM said in a press release. \nThe opening of the West Island branch "is thus planned for the spring of 2024, rather than fall 2023" and "the complete segment up to Deux-Montagnes will be put into service in the fall of 2024, rather than at the end of 2023."\nIn addition to these, pandemic-related restraints have contributed to further construction delays. \nThe South Shore branch, from Brossard to the Gare Centrale, is now projected to open in the spring or summer of 2022, "rather than the end of 2021."\nFinally, the REM expects the airport branch will open by the end of 2024 instead of the end of 2023.\nWhile the construction is delayed, the first train tests will continue as planned along the South Shore segment. \nAccording to the REM, "teams are working diligently to find ways to make up for lost time."