Bad weather shouldn't cause more than 1800 deaths in the world's richest country. Five years on from Hurricane Katrina Tom Heap investigates the real reasons for the New Orleans death toll. It may be classified as a natural disaster but the famously fractious locals agree on one thing- nature had nothing to do with it. They suggest corruption, complacency and the nagging suspicion that a dirt poor, predominantly black city could never expect much help from Washington's power brokers. In the first of a new series of 'Costing the Earth' Tom Heap returns to the city to dig a little deeper, identify the villains and gauge the city's chance of surviving the next big storm. Should the oil industry shoulder the blame? Decades of oil extraction from the Louisiana coast has lowered the land, leaving it more vulnerable to flood and to the depredations of the industry's offshore drilling. How about the US Army? They were charged with building hard defences against a once in 250 year hurricane yet the levees failed throughout the city. Today the same organisation is re-building the defences, this time with a promise to defend the city against a once in a hundred year flood. How can a city rebuild with a promise like that? And what of the wetlands and barrier islands that experts had warned were disappearing fast, leaving the coastline unprotected? How many of the $14bn that's flowed through the city are actually being used to rebuild long-term, natural protection for the city? Tom Heap helps the people of New Orleans in their search for answers.