Provincial police are seeking authorization to proceed with an investigation for alleged criminal negligence in the propane facility explosion in Saint-Roch-de-l'Achigan, Que., Radio-Canada is reporting.
Police suspect there were errors of omission in the work conducted before the explosion, according to Radio-Canada sources.
Two employees and a subcontractor are still missing since the blast that happened on Thursday.
On Sunday morning, staff of the Bienheureuse Marie-Rose Durocher parish organized a mass at the Saint-Roch-de-l'Achigan church on Principale Street to pay tribute to the victims.
Mayor Sébastien Marcil spoke at the service and said the small town is like a family "missing some of its members." He said waiting for answers and being left in the dark has been "extremely difficult."
"You can't imagine how hard it is to not have news about people you love for three days, knowing there's an explosion and the people you know are there," said Marcil.
Asked about the alleged criminal negligence investigation launched by the Sûreté du Québec (SQ), MNA for Rousseau Louis-Charles Thouin said as he was leaving the ceremony that it was important to take "time to do the necessary checks."
The Lafortune family, who own Propane Lafortune, declined to comment on the possible investigation.
Father Claude Ritchie led the mass attended by residents and political figures, including the mayor of Saint-Roch-de-l'Achigan, Sébastien Marcil and MP for Montcalm Luc Thériault.
"[We can] be there and tell people they are not alone, that we consider their pain, their sorrow, their sadness. We share all this together," said Ritchie.
"It's a moment of solidarity and communion with people who are suffering, but it's also a moment when we want to put a little hope in people's hearts," said Pierre Gosselin, a seminarian-in-training who organized the mass.
On Friday, a spokesperson for the SQ said that weather conditions complicated the search for the missing victims in the rubble.