KITCHENER, Ontario -- Three people in Kitchener, located 90 kilometers (58 miles) west of Toronto, are suffering from legionnaires' disease, DPA quoted the officials as saying on Sunday.

Two men, aged 34 and 47, developed symptoms of the disease after working on the roof of the Grand River Hospital at Kitchener, and a 44-year-old woman is under observation after developing symptoms while staying in the hospital.

Both men are in a critical state. The woman, who became ill on Saturday, has now left intensive care, a chief official with Ontario's health authority for the Waterloo region, Doctor Liana Nola said.

Authorities are unsure whether the woman was infected with Legionnaire's disease during her stay in hospital, or if she was already sick.

Legionnaires' disease -- first discovered at an American legion convention in July 1976 where 29 people died -- causes high fever, dry cough, lung congestion and subsequent pneumonia.

It is commonly spread through contaminated air conditioners and ventilators, and is treated with antibiotics.