Rescuers scoured a devastated central Texas landscape of mangled trees, overturned cars and muck-filled debris Saturday in an increasingly bleak mission to locate survivors, including 27 girls who have not been seen since their camp was slammed with a wall of water in a historic flash flood.

At least 43 people have died and dozens of children are missing in the Texas Hill Country after catastrophic flooding, with officials warning the casualty count will climb as forecasts call for more rain and the risk of further flash floods in the coming days.

Texas Governor Greg Abbott said he had asked President Donald Trump to sign a disaster declaration, which would unlock federal aid for those affected.