October 20, 2023 – The St. Lawrence Seaway Management Corporation (SLSMC) was served with a 72-hour notice to strike by Unifor on October 18, for locals 4211, 4319, 4212, 4323 and 4320. The union intends to begin strike action as of 00:01 on Sunday, October 22. As a result of Unifor’s strike notification, SLSMC has started implementing its detailed plans for an orderly and safe shutdown of the system within the 72-hour notice period. Should the unionized workers proceed with strike action, the St. Lawrence Seaway will be closed to all traffic.