August 28, 2006 | Mourners gather on top of a levee in New Orleans, Louisiana, for a candlelight vigil honoring those lost in Hurricane Katrina. Bells tolled in this shattered city Tuesday morning, marking the moment one year earlier when New Orleans' levees buckled and unleashed a torrent of water that ripped homes from their foundations and sent half the city into an uncertain exile. (Photo: Mario Tama / Getty Images)