Twelve jurors convened in the Lac-Megantic railway disaster trial are set to begin their first day of deliberations in a Sherbrooke, Quebec courthouse.
Tom Harding, Richard Labrie and Jean Demaitre are charged with criminal negligence in the tragedy that killed 47 people in July 2013 when a runaway train carrying crude derailed in Lac-Megantic and exploded.
They have pleaded not guilty.
Harding was the train's engineer, Labrie the traffic controller and Demaitre the manager of train operations.
The Crown contends Harding failed to perform a proper brake test and didn't apply enough handbrakes after he parked the 73-wagon convoy on July 5, 2013.
Labrie and Demaitre are accused of failing to ask enough questions to ensure the train was properly secure after a fire broke out on the locomotive and firefighters shut off its engine, compromising the braking system.
The trial began Oct. 2.