IE 11 Not Supported

For optimal browsing, we recommend Chrome, Firefox or Safari browsers.

More Lessons From Hurricane Katrina

A new study has found that 67% of the fatalities in New Orleans after Hurricane Katrina hit in August 2005 resulted from direct impacts of the flooding that occurred when the levees collapsed.

Photo: A U.S. Coast Guardsman searches for survivors in New Orleans in the aftermath of Katrina.

As noted in the Wikipedia's entry on the subject, criticisms of the government's response to Hurricane Katrina primarily consisted of condemnations of mismanagement and lack of leadership in the relief efforts and on the delayed response to the flooding of New Orleans. This has continued to be the general view.

"Criticism was initially prompted by televised images of visibly shaken and frustrated political leaders, and of residents who remained stranded by flood waters without water, food or shelter," notes the online entry. "Deaths from thirst, exhaustion, and violence, days after the storm had passed, fueled the criticism, as did the dilemma of the evacuees at facilities such as the Louisiana Superdome and the New Orleans Civic Center."

Years later, however, we are still discovering more about the Katrina fatalities, what actually transpired, and how governments might respond better in a similar disaster.

The results of a new investigation have just been publish in the May issue of the peer-reviewed journal Risk Analysis: "Loss of Life Caused by the Flooding of New Orleans After Hurricane Katrina: Analysis of the Relationship Between Flood Characteristics and Mortality."

This found that mortality rates were highest in areas near levee breaches, particularly the severe breaches in the Lower 9th Ward where flooding occurred extremely rapidly and the velocity of the water caused drowning and collapsed buildings. In all, 518 out of the analyzed 771 deaths in New Orleans resulted from direct exposure to the flooding. Another 106 deaths were indirect and occurred in public shelters and hospitals in the flooded area. These fatalities were due to lack of necessary medical services, chronic conditions, stress-induced heart attacks or strokes or violence.

"The elderly were the most vulnerable. Nearly 60% of fatalities were over 60 years and 85% were over 51 years," according to Sebastiaan Jonkman at the University of Delft in The Netherlands and one of the study co-authors. He believes that this was due to elderly people's inability to evacuate easily and their vulnerability if they stayed and tried to survive the hazards of an event of this magnitude.

The research team describes their results as preliminary because the mortality data are incomplete and some of the flooding characteristics are based on simulations. However, they believe that despite the limitations, the results provide important insights into the relationship between flood characteristics and mortality. In particular, contrary to current theory, they found that the Katrina flood was very comparable to historical large-scale floods, including the number of people killed. "Overall, the available data for New Orleans do not support the claim that mortality among those exposed during a contemporary flood event is lower than during historical events," Jonkman explained.

Based on this study, he said that "more specific disaster management strategies are needed to target elderly populations and that the direct impacts of large flooding events can be reduced with improved preparation of health care facilities and systems in and outside of flood-prone areas."