An estimate of 20 girls remained missing after deadly flooding caused “destructive” floods at Camp Mystic in Hunt, Texas, Lt. Gov. Dan Patrick said.

Rescue operations are ongoing in Central Texas after flash flooding along the Guadalupe River left 23 girls from Camp Mystic unaccounted for. Officials say dozens have died as catastrophic floods continue to ravage the Hill Country.

The devastating floods have claimed 24 lives. More than 20 children are missing, and officials say more deaths are expected.