NIAGARA COUNTY, N.Y. -- After two individuals have died after being diagnosed with Legionellosis, the Niagara County Health Department (NCDOH) it is continuing to investigate the cause of the outbreak.

There are now 13 cases of Legionellosis that the NCDOH and the state department of health are still looking into as of Monday.

Forty one facilities with 90 cooling towers have been investigated by the NCDOH Public Engineers, the health department says, to ensure they comply with NYS bacterial monitoring regulations. Several have even been re-checked, says Daniel Stapleton, Niagara County' Public Health Department Director.

Under a state law passed over the summer, health care facilities with towers or tanks storing water for heating and cooling systems must routinely test that water for presence of legionella. During one of the routine tests in October, one of the water towers at Eastern Niagara Hospital tested positive for legionella above the safety limit.

Legionnaires' is a type of pneumonia that is caused by legionella bacteria. This bacteria can be found in cooling towers, water tanks, large plumbing systems and water fountains.

Disinfecting the cooling tower water at Eastern Niagara Hospital proved to get rid of the legionella bacteria, health department officials say. However, they are continuing to monitor the cooling tower closely.