Schools Closing Due To Widespread Flu

Ever see this before?
I’m visiting Knoxville and saw on the news they’re closing schools due to the flu.
Seemed odd, did a search and it is happening.
Happening a bit around the country too.
Schools in at least 12 states close to fight against the flu
More Schools Closing Due To Flu
ELLIS COUNTY, Texas (CBS11) – Stafford and Italy ISD schools will be closed Thursday, February 1 and Friday, February 2 while cleaning crews decontaminate the schools for a high number of faculty and students who are out sick with the flu.
Michigan school closed for two days after widespread flu
Those are just a few out of many cases around the country
Southeast Michigan School and Business Closings