NEW ORLEANS (AP) - On the eve of Hurricane Katrina's third anniversary, a nervous New Orleans watched Wednesday as another storm threatened to test everything the city has rebuilt, and officials made plans to evacuate people, pets and hospitals in an attempt to avoid a 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. Mayor Ray Nagin left the Democratic National Convention in Denver to return home for the preparations.
If a Category 3 or stronger hurricane comes within 72 hours of the city, New Orleans plans to 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 700 buses to take people to safety.
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 possible 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 to recover. Many residents still live in temporary trailers, and shuttered homes still bear the black 'X' that was painted to help rescue teams looking for the dead.
Many people never returned, and the city's population is roughly half what it was before the storm.
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. But they are not built to withstand a storm stronger than Katrina.
Gustav formed Monday and roared ashore Tuesday as a Category 1 hurricane near the southern Haitian city of Jacmel with top winds near 90 mph, toppling palm trees and flooding the city's Victorian buildings.
The storm triggered flooding and landslides that killed at least 11 people in the Caribbean. It weakened into a tropical storm and appeared headed for Cuba, though it is likely to grow stronger in the coming days by drawing energy from warm open water.
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 in shelters to 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.
The oil market also reacted to the threat. Oil prices jumped above $119 a barrel as workers began to evacuate from the offshore rigs responsible for a quarter of U.S. crude production. Any damage to the oil infrastructure or Gulf Coast refineries could send U.S. pump prices spiking, possibly before the busy Labor Day weekend.
"A bad storm churning in the Gulf could be a nightmare scenario," said Phil Flynn, an analyst at Alaron Trading Corp. in Chicago. "We might see oil prices spike $5 to $8 if it really rips into platforms."
Many residents hadn't yet made a decision about leaving. Lawson "Sonny" Brannan, a construction company owner, was busy renovating a client's home Wednesday, just blocks from where a levee was breached in the Lakeview neighborhood. A wall of water up to 15 feet deep wiped out the home.
Brannan calmly went about his business, but nonetheless kept a watchful eye on the weather.
"I'm not going to worry about it until I see it in the Gulf," he said. "Then I'll make my decisions."