Man electrocuted as Zeta pounds US

At least one person has died after Hurricane Zeta struck the US Gulf Coast, with rain and winds destroying power lines and damaging buildings.

Zeta had top sustained winds of 175km/h as a Category 2 hurricane at landfall and is the 27th named storm of a historically busy Atlantic hurricane season.

It set a new record as the 11th named storm to make landfall in the continental US in a single season, well beyond the nine storms that hit in 1916.

A Louisiana coroner said a 55-year-old man was electrocuted by a downed power line in New Orleans, and officials said life-threatening conditions would last into Thursday.

St Bernard Parish President Guy McInnis said emergency workers were doing their best to respond to reports of people in distress after their roofs were blown off.

"Guys, we received the brunt of Zeta, and Zeta gave us a good punch," he told WDSU-TV.

Roads were flooded near the coast, where forecasters said Zeta made landfall around Terrebone Bay near Cocodrie, a fishing village at the end of a highway.

Streams of rainfall ran off roofs in New Orleans' famed French Quarter, signs outside bars and restaurants swayed back and forth in the wind and palm trees along Canal St whipped furiously.

With much of the city in the dark and more than 200 trees reported fallen, New Orleans mayor LaToya Cantrell implored residents to stay home and let city officials assess the damage instead of people going out and doing it themselves.

"Although we have made it through, we have been damaged, we have been hit," she said.

More than 875,000 customers were without electricity in Louisiana, Mississippi and Alabama, including about 350,000 in metro New Orleans.

Zeta weakened to a Category 1 hurricane with winds of 145km/h as it moved into southern Mississippi a few hours after landfall, but forecasters said it remained a life-threatening storm.