In the final part of our special series "After the Storm," CNN's Sean Callebs takes a look at New Orleans Mayor Ray Nagin, who is facing his last hurricane season as mayor. He talks about his failures and successes, what he would do differently and what kind of shape he is leaving the city in.

In our special series "After the Storm," we're taking a look at how New Orleans is bouncing back – four years after Hurricane Katrina nearly drowned the city.

The devastation has been well-documented, but the city's school system was crumbling even before the storm hit. And as CNN's Sean Callebs tells us, Katrina was a new beginning.

This week marks four years since Hurricane Katrina took its deadly toll on New Orleans. And in many places around the city the wounds are still fresh.

Today in our special series "After the Storm," our Dr. Sanjay Gupta reports the city's medical system is piecing itself back together. And it's doing it one clinic at a time.

Four years ago this week, New Orleans was decimated by Hurricane Katrina. 80 percent of the city was under water after the hurricane came roaring through.

According to the government, more than 1,800 lives were lost to Katrina, which caused an estimated $100 billion in damage. Many believed the city would never recover.

We're in New Orleans all this week for our special series "After The Storm." Today, CNN's Sean Callebs reports that while the rest of the country languishes in a recession, New Orleans actually shows signs of growth after Katrina.