Months worth of heavy rain fell in a matter of hours on Texas Hill Country, killing at least 13 people and leaving more than 20

According to Lt. Gov. Dan Patrick, at least 20 children are unaccounted for at Camp Mystic, an all-girls camp of 750 campers. He says this does not mean they've been lost. "They could be in a tree. They could be out of communication. We're praying for all those missing to be found alive," he said.

Multiple fatalities have been confirmed and frantic water rescues and searches were underway Friday as a "catastrophic" flooding emergency unfolded.