(CBS) – An entire suburban school has been shut down by the flu.

More than a quarter of the student body called in sick Monday at Nazareth Academy in La Grange Park.

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The school president, the spokesperson, even the principal’s daughter were all sick with symptoms of flu. Twenty-five percent of students stayed home Monday.

So, at 2 p.m., instead of holding regularly scheduled Mass, students and staff were dismissed.

The principal says they wanted to do what they could to stop the illness from spreading even further.

Tuesday and Wednesday the school will get a scrub-down. The principal says Nazareth plans to reopen Thursday.

She urges students and their families to check emails and social media for updates. No school means many school after-school activities have also been cancelled.

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