09/11/2012 05:48 EDT | Updated 11/11/2012 05:12 EST

Quebec reports 12th death from legionnaires' disease

QUEBEC - Public health officials in Quebec City have confirmed a 12th death from legionnaires' disease.

However, a spokeman for the regional public health authority says the situation is under control since the recent inspection of cooling towers in large buildings in the core of the provincial capital.

The authority says 176 people have been diagnosed with the disease since July 17. But no new people have been found with symptoms since Aug. 29.

The source of the disease has not been positively identified.

The deadly bacteria grows in the stagnant water of cooling systems and spreads in little droplets through air conditioning.

Local authorities have disinfected the systems in more than 100 buildings.

Experts are also checking to see if recent excavation work in the area might also have been behind the outbreak.