CHICAGO (CBS)– Two Chesterton, Indiana schools and an administration center were closed after an employee self-reported a positive test for Legionnaires’ disease.

According to Bridget Martinson, a spokesperson for the Duneland School Corporation, preliminary test results indicate “traces of legionella bacteria was present in the water system at Chesterton Middle School and in the cooling tower at Westchester Intermediate School.”

These results led to the decision to close Westchester Intermediate School, Chesterton Middle School and the Duneland School Corporation Administration Center on Friday.

The other schools in the district will remain open.

“For safety purposes, DSC arranged for legionella bacteria testing by an environmental testing company in the employee’s workplace and other district facilities that are characterized as high-risk for this type of bacteria due to the physical characteristics of the facility,” Martinson said in a note to parents.

The spokesperson said students and staff at Chesterton Middle School and Westchester Intermediate School will conduct an eLearning Day on Friday.

Officials urge staff or students experiencing pneumonia-like symptoms to seek medical attention as a precaution.

School officials said additional information will be available on the DSC website.

Parent Heather Thompson told CBS 2 her child attends Bailly Elementary, just blocks from both schools that shut down Friday.

Despite the school’s proximity, class was still in session and all seven other schools in the district, something Thompson finds disconcerting.

“Why are some of them going to school and some of them not,” she said.