School District U46 officials closed three schools midmorning Wednesday after high levels of Legionella, the bacteria that causes Legionnaire's disease pneumonia, was found in the cooling water of their air conditioning cooling towers at those buildings.

In a press conference, Wednesday afternoon, CEO Tony Sanders Sanders said water from the air conditioning systems is routinely tested at the start of each school year. Samples were taken in the district's 53 schools on Sept. 8, but the results did not come in until Wednesday morning.

The district expects the schools to re-open this Friday after the cooling towers are cleaned.

More details here.