A strike is under way at Canada's largest railway.
About 3,200 conductors, train personnel and yard workers with Canadian National Railway hit the bricks at midnight after failing to reach a contract agreement with the Teamsters Canada Rail Conference.
The union says CN has been unwilling to address workers' health and safety issues.
Specific concerns include long hours, fatigue and allegedly dangerous working conditions.
The union has said passenger rail services, including commuter rail services in Toronto, Montreal and Vancouver, would not be affected by the strike.