Last summer's deadly outbreak of Legionnaires' disease was "without precedent," according to Quebec City's public health director, François Desbiens.
Desbiens has released 10 recommendations for the Quebec government after analyzing the outbreak in Quebec City.
The spread of bacteria that began in July affected 181 people and killed 13 in an eight-week period.
"All our thoughts are with the victims of Legionnaires' and their families this morning," Desbiens said.
One building, known as Complexe Jacques Cartier, has been linked to the outbreak by public health officials. Tests found unacceptably high levels of the bacteria in one of four buildings tested in the area.
Desbiens said the five-storey building's rooftop cooling tower — part of the ventilation system and a design common to many commercial and industrial buildings — has been disinfected twice and the owners have fully co-operated with authorities.
Desbiens said he is not laying blame on anyone for the outbreak, and that ultimately a coroner's inquest will determine who, if anyone, is responsible.
The building's owner, Centrale Syndicats du Québec, said it was not taking any responsibility for the Legionnaires' outbreak.
Daniel Lafrenière, the man in charge of the building located on Saint-Joseph East, said the firm used to care for the cooling systems followed all of the guidelines in place.
He said the water in rooftop cooling towers that spread the bacteria was not tested for the Legionella bacteria because public health authorities never recommended it.
The coroner's inquest is due to take place in March.