Flash floods happen when heavy rains unleash more water than the ground can absorb, causing that water to pile up and flow to low-lying areas

In Kerr County, home to youth camps in the Texas Hill Country, searchers have found the bodies of 68 people, including 28 children, Sheriff Larry Leitha said Sunday afternoon. Fatalities in nearby counties brought the total number of deaths to 79 as of Sunday evening.

Central Texas, with its rocky soil, steep terrain and susceptibility to heavy rain, has been prone to devastating floods over the decades.