The decision was made after consultation with Knox Public Health Health Commissioner Julie Miller, Seder said. They arrived at a number of 20 percent or above absenteeism due to flu over a period of several days as the threshold to close the school.

Columbia had 24 percent flu-related absenteeism Tuesday, 27 percent Wednesday and 25 percent Thursday, Seder said.

Other schools in the district have had absentee rates due to flu above 20 percent, but only for a day or two, Seder said.

Seder notified parents of the closing in a letter and also posted a notification via social media. Columbia is scheduled to reopen Monday.

Seder said the decision was not taken lightly, as closing schools for a day “can create additional burdens for families.” Faculty and staff will be in today to give the school a “deep cleaning” following Ohio Department of Health protocols, Seder said.

It is not believed the flu cases are in any way connected to the coronavirus that originated in China. Seder said no one at Columbia has visited China recently.