Over 120 people have died after heavy rain pounded Kerr County, Texas, early Friday, leading to "catastrophic" flooding, the sheriff said.

Federal regulators repeatedly granted appeals to remove Camp Mystic’s buildings from their 100-year flood map, as the camp operated and expanded in a dangerous flood plain.

On the night the deadly floodwaters raged down the Guadalupe River in Texas, the National Weather Service forecast office in Austin/San Antonio was missing a key member of its team: the warning coordination meteorologist,

The risk of the catastrophic flooding that struck Texas Hill Country as people slept on July 4 and left at least 120 dead was potentially underestimated by federal authorities, according to an ABC News analysis of Federal Emergency Management Agency data, satellite imagery and risk modeling.

Here's what to know about the deadly flooding, the colossal weather system that drove it and ongoing efforts to identify victims.

Gov. Greg Abbott announced the federal declaration Friday after formally requesting it for the Austin-area counties Thursday afternoon.

President Donald Trump is touring the devastation left by flash flooding in central Texas amid growing questions about how local officials responded to the crisis as well as questions about the federal response -- including the fate of the Federal Emergency Management Agency -- that he has so far avoided.

Forecasters warn that slow-moving storms could bring heavy downpours to already saturated areas, increasing the risk of flash flooding.