FEMA records obtained by NBC 5 Investigates show that Kerr County officials did not use FEMA’s Integrated Public Alert & Warning System to send warnings with safety instructions to all mobile phones in the affected area during critical hours as the flooding began on July 4.Researchers who have studied the cell phone warning system told NBC 5 Investigates that policies on how and when to issue critical alerts vary widely from one county to another, potentially risking delays when seconds count
