New Orleans, or what's left of it, awoke Friday to discover that fire had been added to the array of pestilences - floodwaters, hunger, looting and mass death - that have beset the city since Hurricane Katrina's winds ripped it apart five days ago.

The plumes of smoke rising from locations on both sides of the river were offset by the belated arrival of long-promised National Guard units in a bid to further the evacuation and reverse the virtual anarchy that descended over the city as beleaguered and increasingly angry local officials begged for federal assistance.

New Orleans: A chemical plant in the 3400 block of Charles Street burns after exploding Friday. Given the lack of firefighting resources in a city without water, a potentially greater threat was the fire that errupted in a low-rise sandwich shop nestled among hotels and office towers in the heart of the Central Business District, just yards from the sprawling Harrah's New Orleans Casino. (Staff photo by Alex Brandon)

On a daylong tour of New Orleans and the stricken Gulf Coast, President Bush conceded that the nation's disaster response had been a disappointment and vowed a redoubled relief effort.

"What is not working, we're going to make it right," he said after an initial landing in Mobile, Ala. His wife, Laura Bush, echoed the same theme in remarks during a visit to Lafayette.

There were continued signs of the efforts to restore order.

Guns pointed skyward in the back of troop transport vehicles, Friday's initial deployment of about 7,000 soldiers from all over the country first moved in on the Ernest N. Morial Convention Center, where they encountered a small city of angry and desperate refugees along a boulevard littered with now putrefying corpses.

Soldiers offloaded pallets of food and water, in some cases tossing the supplies at upwards of 15,000 refugees seething from their exposure to subhuman conditions brought on by lack of sustenance and sewerage.

A motorcade of 95 air-conditioned buses broke away from the troop transport vehicles they had been following and made for the Superdome, the city's shelter of last resort, to complete an evacuation that on Thursday had pared back a refugee population that peaked at about 25,000.

The show of force began to yield results, but not without incident. One unit in a five-bus caravan had reached Opelousas when it flipped on its side, killing one passenger and injuring 17 others.

Other convoys carried 4,200 people to airstrips for further evacuation out of the region, and by early evening the Superdome was expected to be empty, Brig. Maj. Gen. Mark Graham, deputy commander of the National Guard's Katrina Task Force, said late Friday afternoon. The Convention Center throng was reduced by 1,000, he said. In addition, a fleet of six small planes - soon to be expanded to a dozen - airlifted 438 patients from city hospitals.

The Coast Guard continued to ply flooded neighborhoods working alongside a private flotilla of several hundred boats to pluck survivors from rooftops, attics and highway ramps and bridges. By Friday, the tally of those rescued by the Coast Guard had topped 4,000, Capt. Sharon Richey said.

If New Orleans was the epicenter of misery and chaos, reports from more remote suburbs revealed that the death and looting was not limited to the region's big city.

With unofficial death toll estimates rising into the thousands, State Sen. Walter Boasso said at least 100 corpses had been collected in St. Bernard Parish, 25 having been tethered together to keep them from floating away.

"We've had people lying in water in the attic for days," Boasso said of the continuing rescue effort.

Amos Cormier, chairman of the governing council in Plaquemines Parish, the finger of land that stretches downriver to the mouth of the Mississippi , arrived Friday in Baton Rouge seeking a long list of supplies, his top request a satellite phone. Other items urgently needed: 50 military police, 50 assault rifles, 50 sharpshooters, dynamite and at least 200 body bags.

Cormier said the lower half of the parish was entirely underwater and that virtual piracy had broken out as looters arrived by boat and began grabbing maritime supplies and even yachts and trawlers - "whatever they can take," Cormier said.

The dynamite would be used to blow holes in the marsh-side levees below Myrtle Grove, hastening drainage of floodwaters, said Cormier, who acknowledged that, as options go, dynamite is less than ideal. The Army Corps would prefer that the levees be breached by excavation to make their rebuilding more manageable. Cormier said that was fine with him -- "if they can get in" with the heavy equipment needed for the job.

Back in Orleans Parish, floodwaters continued to drain from the city into Lake Pontchartrain through breaches punched in the levee system, but the process, even after the now-defunct city pumps begin working, will take 36 to 80 days, authorities said, fine-tuning an initial estimate that the process would take up to two months. Johnny Bradberry, secretary of the state Department of Transportation Development, said the pumps may be working as early as Monday.

To keep high tides - or another hurricane -- from pushing the lake back into the city, Boh Brothers construction company raced Friday to complete installation of sheet metal piling below the Old Hammond Highway bridge over the 17th Street Canal. The waterway between Orleans and Jefferson parishes was the scene of the most spectacular and devastating failure of the city's flood protection system. The breach was attacked by dropping 3,000 pound sacks of sand - 200 of them - into the chasm eaten into the side of the canal by roiling water. Officials said the hole should be plugged by late Sunday or Monday.

Mayor Ray Nagin, meanwhile, predicted that electrical power in the city would not be restored for two to three months. Jefferson Parish also abandoned rosier projections and said residents should not plan to visit the parish Monday, even for the temporary check- up on their homes that had been announced in the immediate aftermath of Katrina's landfall.

Some of the fires that had sent smoke into the morning skies were still burning by late afternoon, and another appeared to have erupted and spread to several houses in the area of Notre Dame Seminary on Carrollton Avenue.

The first of the day's fires, announced by an explosion that rocked a wide area of the city, consumed a warehouse along the levee in the city's downriver Bywater area and spread to a second. State officials with the Department of Environmental Quality flew a helicopter over the building, formerly a storage depot for oil products, and determined that its emissions were not toxic, and fireboats appeared to have brought that conflagration under control by late afternoon.

Given the lack of firefighting resources in a city without water, the potentially greater threat was the fire that erupted in a low- rise sandwich shop nestled among hotels and office towers in the heart of the Central Business District, just yards from the sprawling Harrah's casino. Another fire of undetermined origin sent smoke rising into cloudless morning skies across the Mississippi River on the West Bank of suburban Jefferson Parish, which already has seen an entire shopping mall torched by looters.

The Mississippi River on Friday was opened to closely restricted navigation up to mile 235, the Coast Guard announced, good news for some 90 vessels that have been idled at its mouth. Some of them would be tankers bearing crude oil to refineries and a possible respite in gas prices that soared above $6 a gallon at some stations Friday.

Another statistic on the oil front suggested that the shortages, even with resumed tanker traffic, could be long-lasting. Katrina knocked 28 offshore oil platforms from their moorings; 30 more were lost altogether, industry officials said.

Other economic indicators were comparably grim. The loss attributable to the storm was set at $100 million by Risk Management Solutions and state officials with the Department of Labor were bracing for the worst as unemployment claims, usually at about 4,000 a week, soar to a projected 750,000 all told.

As they have all week, survivors of the holocaust on Friday continued to stagger into cities and towns all around the rim of Hurricane Katrina's arc of destruction, gazing back at their former lives in anger, sorrow and disbelief.

One among the thousands was Mark Perillat, a 49-year-old Bywater resident. After sending his wife and children to Lake Charles, he had stayed on in their home for three days, venturing out repeatedly into flooded neighborhoods by canoe to rescue trapped people and deliver them to overpasses, bridges - anywhere he could drop them. One canoe load, a couple in their 50s, had stood for three days in neck-deep water, he said.

As a cable television station rebroadcast the tearful and bitter Thursday night tirade in which Nagin lambasted federal officials for their lack of effective response and then burst into tears, Perillat cheered the mayor -- "that's my guy" - and then broke down himself.

"Weathering storms, getting people out of the water, that's okay," Perillat said after regaining his composure. "The worst thing is not being able to deal with this on a national level. The government let us down, the whole f----- city."