Roch Bernier, one of the co-owners of the Residence du Havre, says people have a right to know the real story behind the Jan. 23 blaze.
Bernier is part of a $3.8-million lawsuit against the town of L'Isle-Verte. The suit alleges the community failed to implement emergency plans which might have lowered the death toll.
An insurance company is also involved in the lawsuit and is seeking $2.3 million of the $3.8 million.
Investigations into the tragedy are already being carried out by Quebec provincial police, the coroner's office and the fire commissioner.
Bernier attended a news conference in Quebec City on Monday with his lawyer, Guy Bertrand, and urged Premier Philippe Couillard to call the public inquiry.
Bertrand said he doesn't understand why the investigations into the fire have taken so long.
"An inquiry like that doesn't take seven months," he said. "It's completely unacceptable."
He said a public inquiry would point out "troubling and serious facts" that would support the theory of negilgence on the part of L'Isle-Verte and its fire department.
In the lawsuit, Bernier alleges the L'Isle-Verte fire department was not adequately equipped to deal with the fire at the seniors' residence, where many of the elderly inhabitants had limited mobility.
Bernier said Monday it is "not easy" to cope with the tragedy.
"I even avoid going into town," he said. "It's very difficult. I don't mind saying the tears flow often."
Bernier said he's frustrated because he can't get answers to questions about such things as the fire department response time to the blaze.
He recalled how on the night of the fire he saw some people burned alive and others jumping from the upper floors to escape the flames.
"Where were the firefighters?" he asked.
He said the owner of such a residence "can't do everything alone so the municipality has a large responsibility."