NEW ORLEANS - Progress was measured in inches Tuesday, in the slow dropping of water levels outside New Orleans' buildings, as engineers struggled to drain this saucer of a city in a Herculean task that could take weeks - if they are lucky.
The Army Corps of Engineers said the timetable ranges from three weeks to nearly three months, depending on a string of variables, including rainfall, the still-unknown condition of the pumps abandoned to Hurricane Katrina, and whether the system can withstand the flotsam of broken buildings, trees, trash and corpses.
Work has also been impeded by sporadic gunfire coming from "criminals with guns," said Col. Richard Wagenaar, the corps' chief district engineer.
Despite complications, "we have to get the water out of the city or the nightmare will continue," said Louisiana Environmental Secretary Mike McDaniel. He said the water will be pumped into Lake Pontchartrain even though it is fouled with sewage, gasoline and other dangerous substances.
The pumping began after the corps used hundreds of sandbags and rocks over the Labor Day weekend to close a 200-foot gap in the 17th Street Canal levee that burst in the aftermath of the storm and swamped 80 percent of this below sea-level city.
Following an aerial tour Tuesday, Mayor Ray Nagin said the water was dropping slightly, and he estimated it now covered only 60 percent of the city.
"Even in areas where the water was as high as the rooftops, I started to see parts of the buildings," he said. "I'm starting to see rays of light."
But he also warned of the horrors that could be revealed when the waters recede.
"It's going to be awful and it's going to wake the nation up again," said Nagin, who a day earlier upped his estimate of the death toll in his city to as much as 10,000.
The job to rid the city of an estimated 30-billion gallons of water got off to a slow start.
Once all of the city's pumping stations are running, they can lower the water level a half-inch per hour, or about a foot per day. But by late Tuesday afternoon, corps officials said only three of New Orleans' normal contingent of 148 drainage pumps were operating.
With the water dropping, military and police turned their attention to evacuating the streets of the estimated 10,000 people still thought to be in the city. Some have been holed up in their homes and refuse to leave.
"You've got to protect your property, that's the main thing," said 69-year-old John Ebanks, who waved off would-be rescuers from a porch stocked with food, mosquito spray and other supplies. "This is all I've got."
In a plea to holdouts who might be listening to portable radios in the powerless city, Nagin warned that the fetid water could carry disease and that natural gas was leaking all over town.
"This is not a safe environment," Nagin said. "I understand the spirit that's basically, "I don't want to abandon my city.' It's okay. Leave for a little while. Let us get you to a better place. Let us clean the city up."
To that end, the Pentagon began sending 5,000 paratroopers from the Army's storied 82nd Airborne Division to use small boats, including inflatable Zodiac craft, to launch a new search-and-rescue effort in flooded sections of the city.
Some National Guardsmen and helicopters were diverted from their search missions Tuesday to fight fires, an emerging threat in a city that is still at least a day and a half away from restoring the first running water since the storm.
New Orleans Police Superintendent Eddie Compass said lawlessness in the city "has subsided tremendously," and officers said those caught looting in an area where the governor has declared an emergency can get 15 years in prison. About 124 prisoners filled a downtown jail set up at the city's train and bus terminal.
"We continue to get better day by day," Compass said.
Five of the 13 subbasins in New Orleans were still seriously flooded, and barges and crews were getting into place to fix levee breaches at two other spots - the London Avenue canal and the Industrial canal. The London Avenue canal is in the northwestern section of the city, the Industrial canal in the east.
The corps is concentrating on the London Avenue canal, where workers will spend at least two weeks filling a 45-foot hole with rocks and sandbags, Wagenaar said. Once that is fixed, then more pumps can start running.
Before work can even begin on the Industrial canal two barges pushed onto a bridge by Katrina and a sunken barge need to be removed. The Coast Guard has said 110 barges, ships and boats sank or ran aground during the storm - 67 in the Mississippi River and 43 along the coast.
The levees were deliberately breached in some spots to let the water flow back out into Lake Pontchartrain, where the water level had dropped below that inside the city.
"We're working every avenue to do whatever we can to get things back in order," said Walter Baumy, corps manager for the project. "We're going to accomplish the mission of getting the water out of the city."