FRONTLINE and NPR investigate why the U.S. is more vulnerable than ever to climate change-related storms and how Hurricane Helene became an ominous warning about America’s lack of preparedness. In “Hurricane Helene’s Deadly Warning,” Laura Sullivan goes on the ground in North Carolina in the days after the 2024 storm and speaks with survivors who describe the devastation, fear and shock they experienced at seeing entire communities washed away. She revisits Houston, Texas, where thousands of homes remain in an area that already flooded during Harvey in 2017. Sullivan also returns to Staten Island, where, according to a former FEMA director, the billion dollar rebuilding process may not have been enough to prevent mass destruction should another Superstorm Sandy hit.