A swift-moving flood that swept through the Hill Country of Texas on Friday, killing at least 79 people and leaving many more missing, was a flash flood.

A catastrophic Independence Day weekend in Texas will close with more rain and, in some cases, serious threats including quarter-size hail and high winds. A flash flood watch is in effect to begin the day in a terribly hit part of the state, as well.

This is the first solid number officials have provided regarding campers who remain unaccounted for, after estimating Saturday that it could be as high as 27. There were about 750 children at Camp Mystic when the floods hit,

Search teams plodded through mud-laden riverbanks and flew aircraft over the flood-stricken landscape of central Texas for a fourth day on Monday, looking for dozens of people still missing from a disaster that has claimed at least 78 lives.