Hurricane Isaac is lashing New Orleans as it approaches and pushing flood waters over a rural levee south of the city, where authorities believe some people may be trapped.
The U.S. National Hurricane Center said the storm's center early Wednesday was about 50 miles south-southwest of New Orleans and moving slowly.
Authorities say a storm surge driven by Isaac pushed water over the top of an 18-mile stretch of levee in a thinly populated part of Plaquemines Parish.
The levee is one of many in the low-lying coastal zone. It is not part of New Orleans' defenses.
Plaquemines officials believe some people may be trapped in their homes by the flood but they are not sure how many might still be in the area. Strong wind was hampering rescue efforts.
Wind gusts and sheets of rain pelted the nearly empty streets of New Orleans, where people watched the incoming Isaac from behind levees that were strengthened after the much stronger Hurricane Katrina hit seven years ago to the day.
Water pushed by the large and powerful storm flooded over an 18-mile stretch of one levee in Plaquemines Parish south of New Orleans, flooding some homes in a thinly populated area. No injuries were reported.
Parish President Billy Nungesser said a portion of the roof of his home had blown off. He described wind-driven rain coming into his home as "like standing in a light socket with a fire hose turned on."
Isaac was packing 80 mph winds, making it a Category 1 hurricane. It came ashore at 7:45 p.m. EDT Tuesday near the mouth of the Mississippi River, driving a wall of water nearly 11 feet high inland and soaking a neck of land that stretches into the Gulf of Mexico. Its next major target was New Orleans, 70 miles to the northwest, where forecasters said the city's skyscrapers could feel gusts up to 100 mph.
Isaac's winds and sheets of rain were whipping through nearly empty streets in New Orleans while in neighboring Mississippi the storm pushed Gulf water over sections of the main beachfront highway that runs the length of the state's shore.
Ryan Bernie, a spokesman for the city of New Orleans, said the storm had caused only some minor street flooding before dawn and felled trees but had left roughly 125,000 customers in the city without power.
In Mississippi, the main beachfront highway, U.S. 90, was closed in sections by storm surge flooding. At one spot in Biloxi, a foot of water covered the in-town highway for a couple of blocks and it looked like more was coming in. High tide around 9:30 a.m. was likely to bring up more water.
In largely abandoned Plaquemines Parish, storm surge was piling up against levees between the Gulf of Mexico and the Mississippi River along the boot of Louisiana. A levee on the parish's evacuated east bank had been overtopped.
Plaquemines emergency management spokesman Caitlin Campbell said an 18-mile stretch along the thinly populated east bank was being overtopped by surge. Sheriff's deputies were going house-to-house getting residents who'd remained after an earlier evacuation to move to higher ground. Campbell said no injuries were reported and streets were passable.
Hundreds of thousands of people were without power across the state's southern parishes, including more than 250,000 in New Orleans and its suburbs, power provider Entergy reported.
Tens of thousands of people had been told ahead of Isaac to leave low-lying areas of Mississippi and Louisiana, including 700 patients of Louisiana nursing homes. Mississippi shut down the state's 12 shorefront casinos.
The hurricane promised to lend even more solemnity to commemoration ceremonies Wednesday for Katrina's 1,800 dead in Louisiana and Mississippi, including the tolling of the bells at St. Louis Cathedral overlooking New Orleans' Jackson Square.
As Isaac neared the city, there was little fear or panic.
"Isaac is the son of Abraham," said Margaret Thomas, who was trapped for a week in her home in New Orleans' Broadmoor neighborhood by Katrina's floodwaters, yet chose to stay put this time. "It's a special name. That means God will protect us."
Still, the storm drew intense scrutiny because of its timing __ coinciding with Katrina and the first major speeches of the Republican National Convention in Tampa, Fla., already delayed and tempered by the storm.
Gulf Coast officials warned of the dangers of the powerful storm but decided not to call for mass evacuations like those that preceded Katrina, which packed 135 mph winds in 2005.
"We don't expect a Katrina-like event, but remember there are things about a Category 1 storm that can kill you," New Orleans Mayor Mitch Landrieu said, urging people to use common sense and to stay off any streets that may flood.
Tracy Smith, 26, a New Orleans resident who decided that she and her family would be safer at La Quinta hotel near the quarter than at home, ducked outside shortly after midnight to gauge the storm's severity. Farrell yelled over to her to watch out for a restaurant sign that had become partially detached from a building and threatened to fly off.
Smith, a former deputy sheriff, was trapped for several days with about 100 inmates in a New Orleans jail during Hurricane Katrina, up to her waist in floodwaters. She is still haunted by the experience.
"That's why I was panicked for this storm," she said.
Isaac promises to test a New Orleans levee system bolstered by $14 billion in federal repairs and improvements after the catastrophic failures during Hurricane Katrina. But in a city that has already weathered Hurricane Gustav in 2008, many had faith.
"I feel safe," said Pamela Young, who was riding out the storm in the Lower 9th Ward with her dog Princess in a new, two-story home built to replace the one destroyed by Katrina.
"If the wind isn't too rough, I can stay right here," she said, tapping on her wooden living room coffee table. "If the water comes up, I can go upstairs."
Isaac posed political challenges with echoes of those that followed Katrina, a reminder of how the storm seven years ago became a symbol of government ignorance and ineptitude.
President Barack Obama sought to demonstrate his ability to guide the nation through a natural disaster and Republicans reassured residents they were prepared Tuesday as they formally nominated the former Massachusetts governor as the Republican Party's presidential candidate.
It was unclear what further effects the storm might have on the festivities in Tampa, where, after a day of delays, Ann Romney gave a sweeping speech aimed at showcasing her husband's personal side, and New Jersey Gov. Chris Christie issued a broad indictment of Democrats as "disciples of yesterday's politics" who "whistle a happy tune" while taking the country off a fiscal cliff.
There was already simmering political fallout from the storm. Louisiana's Republican Gov. Bobby Jindal, who canceled his trip to the convention in Tampa, said the Obama administration's disaster declaration fell short of the federal help he had requested. Jindal said he wanted a promise from the federal government to be reimbursed for storm preparation costs.
"We learned from past experiences, you can't just wait. You've got to push the federal bureaucracy," Jindal said.
FEMA Administrator Craig Fugate said such requests would be addressed after the storm.
Obama promised that Americans will help each other recover, "no matter what this storm brings."
"When disaster strikes, we're not Democrats or Republicans first, we are Americans first," Obama said at a campaign rally at Iowa State University. "We're one family. We help our neighbors in need."
Along the Gulf coast east of New Orleans, veterans of past hurricanes made sure to take precautions.
Bonnie Chortler, 54, of Waveland, Miss., lost her home during Hurricane Katrina. After hearing forecasts that Isaac could get stronger and stall, she decided to evacuate to her father's home in Red Level, Ala.
"A slow storm can cause a lot more havoc, a lot more long-term power outage, 'cause it can knock down just virtually everything if it just hovers forever," she said.
Those concerns were reinforced by local officials, who imposed curfews in three Mississippi counties.
"This storm is big and it's tightening up and it sat out there for 12 hours south of us and it's pushing that wave action in and there's nowhere for that water to go until it dissipates," said Harrison County Emergency Operations Director Rupert Lacy.
All along U.S. 90, families stood at the edge of the waves to gawk. The Mississippi Sound, protected by barrier islands, is often as still as a lake, but Isaac began stirring breakers before dawn, as it pumped a storm tide toward the coast. Police struggled to clear public piers where water was lapping at the boards, and resorted to bullhorns to try to get sightseers to leave the beach.
In Theodore, Ala., 148 people had taken refuge Tuesday in an emergency shelter set up at the town's high school.
Charlotte McCrary, 41, spent the night along with her husband Bryan and their two sons, 3-year-old Tristan and 1-year-old Gabriel. She spent a year living in a FEMA trailer after Hurricane Katrina, which destroyed her home, and said she still hasn't gotten back to the same place where she was seven years ago.
"I think what it is," Bryan McCrary said, "is it brings back a lot of bad memories."
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