The jurors at the Lac-Megantic trial have told the judge they are at an impasse in their deliberations.
Quebec Superior Court Justice Gaetan Dumas read a letter from the jurors this afternoon in which they asked him what would happen if they couldn't reach unanimity.
Dumas and the lawyers are now discussing what he should tell the jury, which began deliberating last Thursday.
Tom Harding, Richard Labrie and Jean Demaitre were charged with criminal negligence causing the 2013 tragedy that killed 47 people when a runaway train carrying crude oil derailed and exploded.
All three can be found guilty of criminal negligence causing the death of 47 people, while jurors have the option of convicting Harding on one of two other charges: dangerous operation of railway equipment or dangerous operation of railway equipment causing death.
Harding was the train's engineer, Labrie the traffic controller and Demaitre the manager of train operations.