A ferry worker on the Saint-Augustin River crossing in Quebec's Côte-Nord region has died from an unknown cause, the Société des traversiers (STQ) said.
Two other employees on the same ferry line have also fallen ill with an unexplained illness.
The daily link between the communities of Pakuashipi and Saint-Augustin, accessible only by sea or air, has been suspended until further notice. The link will now be provided by helicopter.
STQ president and CEO Stéphane Lafaut said he can't guess as to what happened.
"We do not know the causes, but what we have done is identify the common point [between the three employees], and the only thing in common is their place of work," he said.
The crossing building has been evacuated, and access is prohibited as a precautionary measure while Quebec's workplace health and safety board (CNESST) is investigating.
The STQ said it has contacted 15 employees who work on the crossing to urge them to undergo a medical evaluation.