When Hurricane Katrina struck in 2005, one victim was political scientist Daniel Aldrich. He had just moved to New Orleans. Late one August night, there was a knock on the door.
"It was a neighbor who knew that we had no idea of the realities of the Gulf Coast life," said Aldrich, who is now a political scientist at Purdue University in Indiana. He "knocked on our door very late at night, around midnight on Saturday night, and said, 'Look, you've got small kids — you should really leave.' "
The knock on the door was to prove prophetic. It changed the course of Aldrich's research and, in turn, is changing the way many experts now think about disaster preparedness.
Officials in New Orleans that Saturday night had not yet ordered an evacuation, but Aldrich trusted the neighbor who knocked on his door. He bundled his family into a car and drove to Houston.
"Without that information we never would've left," Aldrich said. I think we would've been trapped."
In fact, by the time people were told to leave, it was too late and thousands of people got stuck.