NEW : 39 people have been injured , 3 of them critically . NEW : 80,000 people typically fill the county during the Fourth of July weekend . NEW : ( CNN ) -- Washburn typical population is about 17,000 . Washburn , Burnett County 's , Grantsburg and Web Lake were among the hardest hit .
NEW : 39 people have been injured , 3 of them critically . NEW : 80,000 people typically fill the county during the Fourth of July weekend . NEW : Washburn typical population is about 17,000 . Washburn , Burnett County 's , Grantsburg and Web Lake were among the hardest hit .