When Hurricane Harvey overwhelmed official rescuers in 2017, thousands of Louisiana civilians loaded their own fishing boats onto trailers and drove to Texas. They set up a command centre in a Costco parking lot in Baton Rouge, coordinated rescues via Facebook and a walkie-talkie app called Zello, and pulled more than 5,000 people from the floodwaters across Houston, Beaumont, Port Arthur, and Vidor. They called themselves the Cajun Navy.
