New Orleans braces, this time for Gustav

On the eve of Hurricane Katrina's third anniversary, New Orleans watched nervously Wednesday as another storm threatened to test everything the city has rebuilt, and officials made plans to relocate people and pets in an attempt to avoid Katrina-style chaos.

Forecasters warned that Gustav could grow into a dangerous Category 3 hurricane in the next several days and hit somewhere along a swath of the Gulf Coast from the Florida Panhandle to Texas – with New Orleans smack in the middle.

Taking no chances, city officials began preliminary planning to evacuate and lock down the city in hopes of avoiding the catastrophe that followed the 2005 storm.

If a Category 3 or stronger hurricane comes within 60 hours of the city, New Orleans will institute a mandatory evacuation order. Unlike Katrina, there will be no massive shelter at the Superdome, a plan designed to encourage residents to leave. Instead, the state has arranged for buses and trains to take people to safety.

It was unclear what would happen to stragglers. Jerry Sneed, the city's emergency preparedness director, said officials are ready to move about 30,000 people. Nearly 8,000 people had signed up for transportation help by late Wednesday.

Mayor Ray Nagin planned to leave the Democratic National Convention in Denver to return home for the preparations, as did U.S. Sen. Mary Landrieu. Gov. Bobby Jindal declared a state of emergency to lay the groundwork for federal assistance, and put 3,000 National Guard troops on standby.

At a suburban Lowe's store, employees said portable generators, gasoline cans, bottled water and batteries were selling briskly. Hotels across south Louisiana reported taking many reservations as coastal residents looked inland for refuge.

Steve Weaver, 82, and his wife stayed for Katrina – and were plucked off the roof of their house by a Coast Guard helicopter. This time, Weaver has no inclination to ride out the storm.

“Everybody learned a lesson about staying, so the highways will be twice as packed this time,” Weaver said.

Katrina struck New Orleans on Aug. 29, 2005, and its storm surge blasted through the levees that protect the city. Eighty percent of the city was flooded.

Though pockets of the New Orleans are well on the way to recovery, many neighborhoods have struggled. Many residents still live in temporary trailers, and shuttered homes still bear the “X” that was painted to help rescue teams looking for the dead.

Many people never returned, and the city's population, about 310,000 people, is roughly two-thirds what it was before the storm, though estimates vary wildly.

Since the storm, the Army Corps of Engineers has spent billions of dollars to improve the levee system, but because of two quiet hurricane seasons, the flood walls have never been tested.

Floodgates have been installed on drainage canals to stop any storm surge from entering the city, and levees have been raised and in many places strengthened with concrete.

Scientists cautioned that the storm's track and intensity were difficult to predict several days in advance.

But in New Orleans, there was little else to do except prepare as if it were Katrina. The Louisiana Society for the Prevention of Cruelty to Animals was set to begin moving animals inland to shelters in Baton Rouge on Thursday, and more would go to Texas shelters on Friday and Saturday.

“We definitely don't want to wait until Saturday or Sunday to decide what to do,” said Ana Zorrilla, director of the pet-rescue group.

Emergency preparations also were under way along Mississippi's coast. The eye of Hurricane Katrina pushed ashore near the small towns of Waveland and Bay St. Louis, Miss., and along the 70-mile coastline, roughly 65,000 homes were destroyed, and thousands of businesses and hulking casino barges were wiped out.

“We don't need anything of this magnitude to come here,” said Biloxi Mayor A.J. Holloway. “Katrina just devastated us.”