Although Hurricane Katrina, which devastated New Orleans and the southern Mississippi coast in 2005, was the costliest hurricane in U.S. in terms of property damage (more than $81 billion), it was not the deadliest in terms of loss of human life.

In 1900, the Great Galveston Hurricane in Texas killed up to 12,000 people. The storm in the Gulf of Mexico was rated a Category 4 hurricane, featuring storm surges of between 8 and 15 feet and winds of 145 miles per hour at landfall.
The death toll was exacerbated by the lack of an adequate warning system and the abnormally high storm surges.

The Okeechobee Hurricane claimed the lives of up to 3,000 people in September 1928. A Category 5 monster, most of the casualties occurred when a storm surge breached the dike surrounding Lake Okeechobee in southern Florida. With wind speeds of up to 140 miles per hour, the storm killed mostly migrant farm workers and left floodwaters for weeks afterward.

Hurricane Katrina of August 2005 killed at least 1500 people and perhaps up to 1,800, with most of the fatalities occurring in New Orleans and the southern coast of Mississippi. Perhaps the most well-documented natural disaster in history, the response to the catastrophe by both the Federal government and the state of Louisiana have been widely criticized as too slow and inadequate.

The city of New Orleans suffered a huge loss of population (mostly by out-migration) which it has yet to restore.

The Cheniere Caminada Hurricane in Louisiana killed at least 1,400 people and perhaps as many as 2,000 in October 1893. With peak winds of 135 miles per hour, the hurricane smashed into southeast Louisiana near Chenière Caminada, just west of Grand Isle.

Most of the fatalities occurred due to the storm surge.

Another deadly storm for the 1893 hurricane season killed between 1,000 and 2,000 people on the coasts of Georgia and South Carolina. Often called, the Sea Islands hurricane, the storm hit near Savannah, Ga., and featured storm surges of up to 16 feet.

The death toll may have actually been much higher since many of the poor rural people in the area had little means to report casualties. At least 30,000 became homeless.

[Data from National Oceanic and Atmospheric Administration (NOAA)]