Hurricane Isaac sidestepped New Orleans on Wednesday, sending the worst of its howling wind and heavy rain into a cluster of rural fishing villages that had few defences against the slow-moving storm that could bring days of unending rain.
Isaac arrived exactly seven years after the devastation of Hurricane Katrina. The latest storm passed slightly to the west of New Orlean, bringing high winds and sheets of rain.
A levee system, bolstered by $14 billion in federal repairs and improvements after the catastrophic failures during Katrina, appeared to hold. Isaac had top sustained winds of 112 kilometres an hour, just below the hurricane threshold of 119 km/h.
The biggest problems in New Orleans seemed to be downed power lines, scattered tree limbs and minor flooding. One person was reported killed, compared with 1,800 deaths from Katrina in Louisiana and Mississippi.
Police reported few problems with looting. Mayor Mitch Landrieu ordered a dusk-to-dawn curfew just to be sure.
But in Plaquemines Parish, a sparsely populated area south of the city that is outside the federal levee system, dozens of stranded people were rescued by boat in flooded coastal areas.
The storm pushed water over a 28-kilometre levee and put so much pressure on it that authorities planned to intentionally puncture the floodwall to relieve the strain.
The storm knocked out power to as many as 700,000 people, stripped branches off trees and flattened fields of sugar cane so completely that they looked as if tanks had driven over them.
By midafternoon, Isaac had been downgraded to a tropical storm. Even at its strongest, it was far weaker than the 2005 hurricane that crippled the city.
Because its coiled bands of rain and wind were advancing at only 8 km/h - about the pace of a brisk walk - the threat of storm surges and flooding was expected to last into a second night as the immense commashaped system crawled across Louisiana.
Rescuers were waiting for the strong winds to die down before moving out to search for other people.
After wind-driven water spilled over the levee in Plaquemines Parish, state officials said they would cut a hole in it as soon as weather allowed.
Louisiana Gov. Bobby Jindal said as many as 40 people in the area needed to be rescued.
