Rescue teams are resuming their search for victims in coastal communities of the US states of Texas and Louisiana, two days after Hurricane Rita struck.
Nothing but stilts and power lines were left standing in Holly Beach
Only two people are so far reported dead in the region, after the storm missed major population centres.
But low-lying towns and villages in the immediate path of the hurricane have been devastated, and hundreds are still feared stranded.
New Orleans residents were told they could return to some areas of the city.
According to a plan drawn up by city Mayor Ray Nagin, residents can return to the Algiers district and workers to the business district, four weeks after Hurricane Katrina caused massive devastation and flooding.
The plan was delayed for a week by Hurricane Rita, which overcame some flood defences for a second time.
Meanwhile people have already begun to return to Houston, Texas, where fears of a repeat of Katrina's destruction led to a mass evacuation.
'Missed a bullet'
Military helicopter crews, coastguards and volunteers have been scouring the worst-hit areas, where many people are thought to have defied evacuation orders.
Thousands have already been rescued from the region.
In some communities, 90-100% of buildings were destroyed by the high winds, while many low-lying areas in the Louisiana wetlands were under 9ft (2.7m) of water.
Only stilts to hold buildings up were left standing in Holly Beach, Louisiana, the Associated Press said, while in nearby Cameron almost all homes were destroyed.
"This is terrible. Whole communities are gone," Louisiana National Guard head Maj Gen Bennett Landreneau told the agency.
Meanwhile Texas Governor Rick Perry, touring the worst affected areas, said his state had got off relatively lightly.
"Even though the people right here in Beaumont and Port Arthur and this part of Orange County really got whacked, the rest of the state missed a bullet," he said.
One man was reported killed by a falling tree in Texas, while a person died in a tornado in Mississippi caused by the hurricane. No deaths have been reported in Louisiana.
Mr Perry estimated that the state had sustained around $8bn of damage, but predicted that most of the vital oil refineries had been spared and could resume production soon.
In Houston, special routes have been set up to let people enter section by section, as power remains down in parts of Texas, and schools and courts remain closed.
Last week's mass evacuation, involving nearly three million people, created traffic jams stretching as long as 100 miles (160km).
The BBC's Daniella Relph reports from Houston that residents are returning, but to order.
While it is a slow process, it is so far running smoothly though the city is still effectively closed for business.