Hurricane Isaac has been downgraded to a tropical storm but nore before it slammed into New Orleans, lashing the city with 80mph winds and relentlessly drenching its streets.
Thousands of people had already fled low-lying areas to avoid the Category 1 Hurricane, which smashed into the state of Louisiana seven years after Hurricane Katrina devastated the area.
Issac, which made landfall on Wednesday, is less powerful than Katrina but is extremely slow moving - it's travelling at around 6mph - which means that the rainfall and winds could last days.
In spite of the downgrading to storm level, the US National Hurricane Center warned that "life-threatening hazards from storm surge and inland flooding" were still occuring.
Thousands have fled low-lying areas of New Orleans to avoid Category 1 Hurricane Issac
A foot of water has already fallen in New Orleans and on Wednesday morning widespread power outages affecting almost 600,000 were reported across Louisiana.
The upgraded levee system so far seems to be holding out in New Orleans, but one area 20 miles away, Plaquemines Parish, saw up to 40 people stranded by flood water.
The Times-Picayune reported that some have been rescued from the roofs of their houses.
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The Guardian's Tom Dart, reporting from downtown New Orleans, said: "It was almost impossible to walk the banks of the Mississippi in the French Quarter, so fierce was the sheeting rain and wind that truly was howling. Some buildings have minor damage to brickwork and signage."
New Orleans Mayor Mitch Landrieu said on Tuesday: "We don't expect a Katrina-like event, but remember there are things about a Category 1 storm that can kill you."
Many New Orleans citizens stayed in the city, confident in the $14bn flood gates that had been put up since Katrina. Pamela Young, who lives in the Lower 9th Ward, which was hit by Katrina, told the Associated Press she felt “safe.”
"Everybody's talking 'going, going,' but the thing is, when you go, there's no telling what will happen. The storm isn't going to just hit here."
Bryan McCrary and his wife Charlotte, whose home was destroyed by Katrina, took refuge in a shelter with their two children last night, saying the hurricane “brings back a lot of bad memories."
Nearly 1,800 people died when Katrina, which had winds of up to 155mph, ravaged the city in 2005.
Mike Jenkins, a senior producer with The Weather Channel, tweeted that the city was being battered yet again.
He wrote: "Canal St is a giant wind tunnel right now. New Orleans just being hammered relentlessly by rain and howling wind. Noise is unreal."
At least 24 people died when Isaac hit in Haiti and the Dominican Republic.