Dozens of people are dead in central Texas in what officials called a "mass casualty event" after devastating flash floods slammed Hill Country, with water rescues taking place along the Guadalupe River.

Texas Hill Country was beset by death and disaster Friday as at least six people were killed and about 20 girls attending a summer camp were reported missing after months worth of heavy rain fell in a matter of hours.

Months worth of heavy rain fell in a matter of hours on Texas Hill Country, Kerr County Sheriff Larry Leitha said.