Three Illinois schools were evacuated Wednesday morning after higher than normal levels of Legionella bacteria was found during routine air quality testing.

The bacteria were detected in the cooling towers of the schools' HVAC systems, according to WGN and NBC Chicago.

The school district posted a message on its Facebook page, explaining the decision to evacuate the schools immediately.

According to the CDC, Legionella is a bacteria found naturally in the environment, especially in warm water systems. The bacteria can be inhaled via contaminated air.  It is not transmitted from person to person. Legionella can cause a form of bacterial pneumonia known as Legionnaires' disease. Most cases are treatable with antibiotics. Those who have compromised immune systems and the elderly are at the most risk for complications.

Legionella can also cause a flu-like disease called Pontiac fever, which is milder in nature.

According to the CBS Chicago, no reports of illness so far have been reported at the three schools that were evacuated.

About the Author

Keep Reading

(Illustration: Philip Robibero / AJC)

Credit: Philiip Robibero / AJC

Featured

Mathew Palmer, a former Delta Air Lines employee, at his home in Atlanta on Thursday, Oct. 9, 2025.  Palmer was fired less than two weeks after writing a post on social media about the assassination of conservative activist Charlie Kirk. (Natrice Miller/AJC)