Hurricane Isaac surged ashore in southern Louisiana last night packing high winds and heavy rains, and was set to hit New Orleans seven years to the day after Hurricane Katrina devastated the city. Isaac is the first hurricane to make landfall in the United States this season. While not packing nearly the power of Katrina -- which was a Category 3 storm when it slammed the Crescent City on August 29, 2005 -- Category 1 Isaac was nevertheless a powerful reminder of New Orleans' vulnerability.
The hurricane will be the first test for multibillion-dollar flood defences built after levees failed under Katrina's storm surge and left large parts of New Orleans under water.
The National Hurricane Center warned that Isaac and its 80 mph (130kph) winds were producing a dangerous storm surge and that flooding from rainfall would follow.
Isaac will also test the resolve of officials and preparedness of a city where some 1,800 died seven years ago in what was the costliest natural disaster in U.S. history.
Earlier yesterday, officials from Mitch Landrieu, the mayor of New Orleans, to Louisiana Governor Bobby Jindal, to U.S. President Barack Obama, scrambled to get ahead of the storm's impact, mindful of the chaos and botched relief efforts in the wake of Katrina.
Landrieu assured residents that this time around, "your city is secure," and said emergency services were ready for search and rescue missions, if needed.
"We're in the heart of this fight," Landrieu told an evening news conference. "We are in the hunker-down phase."
About 1,000 U.S. National Guard troops in military vehicles took up positions in the mostly deserted streets of New Orleans, brandishing automatic assault rifles to ward off any threat of the looting that spread after Katrina. Police cars patrolled darkened streets with blue lights flashing.
Obama urged residents to take cover and heed warnings, saying that now was "not the time to tempt fate." He issued emergency declarations for Louisiana and Mississippi earlier this week.
PUTTING NEW SYSTEMS TO THE TEST
Isaac's arrival on the seventh anniversary of Katrina cast a spotlight on the enduring struggle of the iconic American city and its residents.
When the 2005 storm hit, the city endured days of chaos, including widespread looting and other crimes. Hundreds drowned while residents waited for days to be plucked from their rooftops by Coast Guard helicopters.
Hundreds of thousands of residents, their homes destroyed by flooding or made uninhabitable by mold, were moved temporarily to Texas and other states. Thousands along the Gulf Coast lived in government provided trailers for months or years afterwards.
After Katrina, the Army Corps of Engineers built a $14.5 billion defense system of walls, floodgates, levees and pumps designed to protect the city from a massive tidal surge like that caused by Katrina.
Yesterday morning, army engineers closed the massive new floodgate at Lake Borgne, east of New Orleans, for the first time. It is largest storm-surge barrier in the world.
Officials have confidently predicted that the systems will stand up to the test, although residents have been wary.
Most of the city's Lower Ninth ward, scarred by memories of Katrina, was deserted on Tuesday. Residents who did not evacuate stocked up on water, food and fuel.
"We've got all kinds of eats and treats," Arthur Anderson, 61, who was trapped in the attic of his house during Katrina before he escaped by boat.
Residents of Louisiana's low-lying Plaquemines Parish, where some flooding was already happening yesterday, were anxious about their homes.
Avenal Terrance, 52, who was evacuated early on Tuesday, is hoping the levee holds. "I'm living in an old trailer, not a new one, and I just hope and pray that the storm doesn't take it," she said.
Others decided to stick it out, some heading for local bars for a spot of courage before hunkering down at home.
"I was here for Hurricane Katrina, so I feel I've seen the worst. This one won't be that bad," said Scott Young, 56.
Young said he had laid in a supply of ice and a tank of fuel for his gas grill, and added that the city seemed better prepared this time around. He said the presence of police and troops made him feel safe.
The storm was traveling at a relatively slow 8 mph, which was a worry as slow-moving cyclones can bring higher rainfall. Landrieu said the city's pumping capacity could cope with about one inch of rain per hour.
Although it only reached hurricane strength on Tuesday, Isaac killed at least 23 people and caused significant flooding and damage in Haiti and the Dominican Republic before skirting the southern tip of Florida on Sunday and heading across the warm waters of the Gulf of Mexico.
Isaac spared Tampa, Florida, where the Republican National Convention is being held, but it forced party leaders to abandon most of Monday's programme, and to tone down what some might see as excess jubilation about Mitt Romney's presidential nomination at a time Gulf Coast when residents faced danger.