When Hurricane Katrina made landfall, city officials of New Orleans were most worried about what aspect of the hurricane due to New Orleans being built below sea level?

The city officials of New Orleans were most worried about the storm surge caused by Hurricane Katrina due to the city being built below sea level. The storm surge is a rise in sea level caused by the hurricane's strong winds and low pressure. In New Orleans, the surge caused levees to fail, leading to catastrophic flooding in the city.