Like a plugged-up old bathtub, the city is slowly draining and leaving behind a filthy layer of debris.

In the Ninth Ward, one of the poorest and hardest-hit areas of the city, members of the Oregon National Guard's 41st Combat Brigade military police have established their base in the courtyard of the Academy of the Holy Angels, a complex of sturdy red-brick buildings that house apartments for the elderly and a convent.

Today, the mission of the guardsmen switched from search and rescue to reconnaissance. Traveling in Humvees, they divided up the area and patrolled every street, noting every downed branch, wire and other obstruction, including abandoned cars, trucks and buses.

They were also on the lookout for survivors.

Staff Sgt. Jeff Shinn, an armored car security guard in civilian life, was in the rear seat directing the operation. Five minutes out of their Holy Angels headquarters, they came across a state animal welfare worker checking on her home.

"I have a neighbor next door who won't leave," Danal Perry said. "I just gave him some water. I wish you would check on him."

Shinn walked a few paces down the sidewalk, stepping around broken branches. Milton Pedersen was inside the front room of his pink duplex. The front door was open, but a metal gate was closed. He was fiddling with a white portable radio the size of a box of animal crackers.

"How are you doing?" Shinn asked. "Can we convince you to leave?"

"No," Pedersen answered. "They are going to turn on the lights soon."

"Did you hear that on your radio?" Shinn said.

"No," Pedersen said. "I saw the trucks out there."

No sound was coming out of the radio as he fiddled. He said he was 57 years old. He was sitting down, shirtless in a pair of shorts. He looked at least 10 years older. He said he had high blood pressure but was doing fine because he had six months' worth of medication. When asked if he was retired, he answered, "You might say that." An empty beer can was at his feet.

"At some point, Mr. Pedersen, they might make you leave," Shinn said.

"I know that," he said. "But I'm not going, because I feel like nothing is going to happen to me in my house."

He said he had drinking water, and there was a box of Meals Ready to Eat on the floor. Shinn wished him well and climbed back into the Humvee.

Every house they drove past on every street they traveled had been checked previously and spray-painted with an "X," indicating it was clear of survivors. Rescuers have marked homes containing bodies with a black circle, but in the 10-square-block portion of the Ninth Ward where Shinn and his men patrolled, not one house was marked with the symbol of death.

Some of the small neighborhood grocery stores with signs advertising cigarettes and beer had been looted. One bore a spray-painted warning: "Uloot, Udead." It had not been touched. Gasoline was a golden commodity in the first 48 hours after the storm, and many of the fuel doors of abandoned cars were open and the gas caps missing. One car had a portion of garden hose hanging out of it, apparently used to siphon out whatever was in the tank.

Two streets down from Pedersen's house, William Chapman, 58, was out in front of his home. He said he had stayed behind to watch the neighborhood and has been helping the National Guard service their vehicles. On the next corner was a small warehouse, and he said that is where he spends his nights, up on the flat roof of the building. A small tent was visible from street level, flapping in the breeze. Chapman said he was armed and should be considered dangerous when it came to protecting the neighborhood.

"Yeah, I got to be," he said. "I got to be able to protect myself. There was a while before you guys [the guardsmen] got here that the only ones around here at night were crazy [expletive]. But I'm right here. I have a gun."

A gas crew was on the next block, going house to house, checking for damage to the lines and meters. New York police officers were walking the streets.

For those who have stayed behind, money is obsolete. No stores are open and so residents are bartering for tree service, trading cigarettes for chain saw service, swapping time on a generator for water or candles.

On Maison Street, Jeff Levinson was sitting on his wide front porch when the Humvee passed.

Shinn climbed out, and before he could say a word, Levinson, 46, looked up and said in a slight New York accent, "I already talked to your colonel -- colonel, oh, I can't remember his name. I'm the guy who supplied you with the cleaning products."

Shinn told him that he was not going to make him leave his home, but someone else might come along and force him to leave in the next couple of days.

"I'm not leaving," Levinson said. "No one told me I had to leave yet, but I know that I am a hunted species. You can't strip every citizen out of the city. It's illogical. This is a city of have and have-nots," he said, and then went on with a five-minute rant about how long it took police and soldiers to get to this neighborhood while the National Guard was in the affluent sections of Uptown within 48 hours.

"But I don't mean to preach to you," he said. "You are doing a good job."

Shinn wished him well and climbed back into the Humvee. Spec. Katherine Czernik was at the wheel, driving through deep puddles and around dangling wires and hanging branches. Pvt. Pat Dean was up in the turret, armed and navigating, and Sgt. Lonnie Paradis was making notes about every street, coding it red for impassable, amber for obstructed and green for clear.

The Humvee was hot as a teapot on the boil. Shinn told Czernik to make a left, and as she did, a street covered with nearly a foot of water appeared ahead. Four days ago, the water level was two or three feet higher. The sun beat down, the stink of the water wafted up through the open windows, and the floodwaters slowly receded, inch by inch, unwrapping the biggest mess anyone could imagine.

J.C. Williams, left, from Colorado's Pueblo County sheriff's office, kicks in a door as he and Pueblo police officer Gerald LeRay look for survivors.A firefighter from San Diego's Task Force 8 peers through a hole in a roof, looking for people.