When storms roll in, water rushes downhill fast, gaining speed and force as it moves — often with deadly results.

KERR COUNTY, Texas – The Hill Country flood, marked by unprecedented rainfall and unfortunate timing, has become one of the deadliest floods in Texas history, with its swift waters catching many off guard in the dead of night.

TEXSAR, an Austin-based nonprofit first responder organization, has deployed swiftwater teams, boats, drones and K9s to help search for missing people. It hopes to raise $100,000 to maintain its operation. Donations can be made online.