When Hurricane Katrina hit New Orleans in August 2005, it swept across the city within a matter of hours, yet within those hours it proved the costliest and one of the five deadliest hurricanes in United States history. 

The catastrophic failure of the flood protection in New Orleans led to an immediate review of the city's design and construction of the flood protection and levee systems. Yet could some of the damage from the disaster have been avoided due to its significant historical underworld?

In this fascinating episode of Cities of the Underworld, we explore New Orlean's underworld in light of this terrible natural tragedy.