Camp Mystic is located in Hunt, Texas; 20 girls are unaccounted for, according to Lt. Gov. Dan Patrick.

Authorities stressed that the situation was still developing and that the death toll could change, with rescue operations ongoing.

At least 13 fatalities were reported Friday as devastating floods slammed Texas' Hill Country with water rescues taking place along the Guadalupe River, officials said. "Within 45 minutes, the Guadalupe River rose 26 feet and it was a destructive flood — taking property and sadly lives,