Rescuers on Monday combed through the "catastrophic" damage Hurricane Ida inflicted on Louisiana, a day after the fierce storm killed at least two people, stranded others in rising floodwaters and sheared the roofs off homes.
New Orleans was still mostly without power more than 24 hours after Ida slammed into the Louisiana coast as a Category 4 storm, exactly 16 years to the day that Hurricane Katrina made landfall, wreaking deadly havoc.
While search and rescue missions focus on those who sheltered in place, local officials urged people who had evacuated not to return yet as there was a lack of services and trees, debris and downed power lines continue to pose a hazard.
"I know people are anxious to get back home, but I am urging you to wait until you get the all clear from your local officials. The storm may have passed but dangers still remain," Louisiana Governor John Bel Edwards said at televised a press conference.
Two deaths have been confirmed as crews began fanning out in boats and off-road vehicles to search communities cut off by the hurricane. A man was also missing after apparently being killed by an alligator.
Images of people being plucked from flooded cars and pictures of destroyed homes surfaced on social media, while the damage in New Orleans itself remained limited.
New Orleans Airport said all incoming and outgoing flights slated for Tuesday were canceled, while airlines had scrapped 197 flights scheduled on Wednesday.
Ida -- which was downgraded to a tropical depression on Monday -- knocked out power for more than a million properties across Louisiana, according to outage tracker PowerOutage.US.
"I was there 16 years ago. The wind seems worse this time but the damage seems less bad," said French Quarter resident Dereck Terry, surveying his neighborhood in flip-flops and a T-shirt, umbrella in hand.
"I have a broken window. Some tiles from the roof are on the streets and water came inside," the 53-year-old retired pharmacist added.
According to Edwards the levee system in the affected parishes had "really held up very well, otherwise we would be facing much more problems today".
- 'Total devastation' -
In the town of Jean Lafitte, just south of New Orleans, Mayor Tim Kerner said the rapidly rising waters had overtopped the 7.5-foot-high (2.3-meter) levees.
"Total devastation, catastrophic, our town levees have been overtopped," Kerner told ABC-affiliate WGNO.
"We have anywhere between 75 to 200 people stranded in Barataria," after a barge took out a bridge to the island.
Several residents of LaPlace, just upstream from New Orleans, posted appeals for help on social media, saying they were trapped by rising floodwaters.
"The damage is really catastrophic," Edwards told NBC's "Today", adding that Ida had "delivered the surge that was forecasted. The wind that was forecasted and the rain."
President Joe Biden declared a major disaster for Louisiana and Mississippi, which gives the states access to federal aid.
One person was killed by a falling tree in Prairieville, 60 miles northwest of New Orleans, the Ascension Parish Sheriff's Office said.
A second victim died while trying to drive through floodwaters in New Orleans, the Louisiana Department of Health tweeted.
In St. Tammany Parish, police said a 71-year-old man was attacked and "apparently killed by an alligator while walking in flood waters following Hurricane Ida".
The man's wife saw her husband being attacked by the reptile and managed to pull him out of the floodwaters, the sheriff's office said in a statement. But he had disappeared by the time his wife came back from trying to get help.
Governor Edwards said on Twitter that Louisiana had deployed more than 1,600 personnel to conduct search and rescue across the state.
US Army Major General Hank Taylor told journalists at a Pentagon briefing that military, federal emergency management officials and the National Guard had activated more than 5,200 personnel in Louisiana, Mississippi, Texas, and Alabama.
- 'Way less debris' -
Most residents had heeded warnings of catastrophic damage and authorities' instructions to flee.
"I stayed for Katrina and from what I've seen so far there is way less debris in the streets than after Katrina," Mike, who has lived in the French Quarter, told AFP Monday, declining to give his last name.
The memory of Katrina, which made landfall on August 29, 2005, is still fresh in the state, where it caused some 1,800 deaths and billions of dollars in damage.
The National Hurricane Center issued flash flood warnings over the Tennessee and Ohio Valleys as Ida travels northeast.
As of 0900 GMT Tuesday, Ida was about 185 miles (300 kilometers) southwest of country music hub Nashville, Tennessee, with maximum sustained winds of 30 miles per hour.
The storm system is expected to track across the United States all the way to the mid-Atlantic through Wednesday, creating the potential for flash flooding along the way.
Scientists have warned of a rise in cyclone activity as the ocean surface warms due to climate change, posing an increasing threat to the world's coastal communities.