The elderly are particularly vulnerable in storms and floods, especially those who live alone, suffer from chronic medical conditions or face physical and mental disabilities, experts said. A 2008 study of deaths from Hurricane Katrina found that nearly half of a representative sample of victims were older than 75.

Florida has among the highest concentrations of senior citizens in the nation. The U.S. Census Bureau estimates there were more than 1.6 million people who were at least 75 years old in Florida in 2015, and it considers almost half of them disabled.

This includes 497,000 people who have trouble walking or climbing stairs, 202,000 people who have trouble bathing or dressing and 221,000 who have trouble concentrating, remembering things or making decisions.