A view of the city at sunset during a blackout after Hurricane Ida made landfall in Louisiana on Tuesday. Reuters

Residents still reeling from flooding and damage caused by Hurricane Ida as Louisiana and Mississippi took stock on Tuesday, as receding floodwaters began to reveal the full extent of the damage along the US Gulf Coast and the death toll rose to four.

As people faced suffocating heat and humidity, South Louisiana braced for a month without electricity and reliable water supplies in the wake of Hurricane Ida, one of the most powerful storms ever to hit the US Gulf Coast.

READ MORE

Hurricane Ida: More than a million without power in New Orleans

Pentagon holds talks with Chinese military official says

New Orleans was under a curfew on Tuesday evening, nearly two days after Ida slammed into the Louisiana coast as a Category 4 storm, exactly 16 years after devastating Hurricane Katrina — which killed more than 1,800 people — made landfall.

An aerial view of the damage caused by the hurricane in southeast Louisiana, on Tuesday. AP

Residents scrambled for food, gas, water and relief from the sweltering heat as thousands of line workers toiled to restore electricity and officials vowed to set up more sites where people could get free meals and cool off.

Power and water outages affected hundreds of thousands of people, many of them with no way to get immediate relief.

"I don’t have a car. I don’t have no choice but to stay,” said Charles Harris, 58, as he looked for a place to eat on Tuesday in a New Orleans’ neighbourhood where Ida snapped utility poles and brought down power lines two days earlier.

Police officers clear out cars in the aftermath of Hurricane Ida in New Orleans, Louisiana, US, on Tuesday. Reuters

President Joe Biden offered federal help in restoring power during a call with Energy Secretary Jennifer Granholm and the chiefs of two of the Gulf Coast's largest utilities, Entergy and Southern Co, the White House said.

At Ochsner St. Anne Hospital southwest of New Orleans, 6,000-gallon tanker trucks pumped fuel and water into tanks to keep its air-conditioning running. The medical center closed to all but a few emergency patients.

New Orleans' restaurants, many shut ahead of the storm, also face an uncertain future because of a lack of electricity and facilities, reviving memories of the difficulties that plagued businesses for weeks in the wake of Katrina.

People clean up a flooded home on Tuesday in Ponchatoula, Louisiana. AFP

"This is definitely feeling like Katrina," said Lisa Blount, a spokesperson for the city's oldest eatery, Antoine's, which is a landmark in the French Quarter. "To hear the power is potentially out for two to three weeks, that is devastating."

More than 1 million homes and businesses in Louisiana and Mississippi were left without power when Ida slammed the electric grid on Sunday with its 150 mph (240 kph) winds, toppling a major transmission tower and knocking out thousands of miles of lines and hundreds of substations.

An estimated 25,000-plus utility workers labored to restore electricity, but officials said it could take weeks.