More U.S. children have died this flu season than at any time since the swine flu pandemic 15 years ago. Those numbers were reflected in a number of states including Minnesota where the spike began just after the Christmas holilday.

The U.S. broke a 15-year record for pediatric flu deaths this season, according to federal data released Friday. There were 216 children who died this season, according to a preliminary

Since flu season is still ongoing, data is preliminary and may change, the Centers for Disease Control and Prevention said. Experts say it will likely increase.