Desperate for fresh air, dozens of refugees from Hurricane Katrina slept on the walkway surrounding the Superdome as conditions inside worsened and thousands more people were brought to the stadium even as Louisiana's governor said Tuesday that the huge emergency shelter and others would have to be emptied.

"Conditions are degenerating rapidly," Gov. Kathleen Babineaux Blanco said Tuesday night in announcing that the estimated 20,000 refugees there would be evacuated to other shelters within two days. "It's a very, very desperate situation."

Refugees had flocked to the Superdome on Tuesday in scenes that seemed biblical in scope, and the population had doubled from Monday, when few realized that the flooding -- and the ranks inside the NFL stadium -- would increase dramatically.

They came loaded in the backs of fatigue green and desert tan Army trucks. Some arrived atop commandeered U-Haul trucks, while others were dropped off after being ferried from rooftops by Coast Guard helicopters. Many more just walked or waded.

The refugees were bedraggled, bereft of belongings and scared, but, despite the filthy restrooms, overflowing trash cans and sweltering conditions, they were grateful for shelter.

Mary Stewart, 80, slid off the back of a National Guard truck with nothing but the clothes she wore, her purse and the shoe on her left foot.

"I was so scared, I don't feel I have any entrails anymore," said Stewart, who spent a harrowing night in the attic of a beauty salon in the city's flooded Ninth Ward.

Beauty salon employee Kioka Williams, 23, said they had to hack through the ceiling to reach the attic as the water rose.

"Oh, my God, it was hell," she said. "We were screaming, hollering, flashing lights. It was complete chaos."

The eight people in the salon were rescued early Tuesday by a police boat.

"I almost died in the night water," Willie Anderson, 49, said as he arrived at the Superdome. He had spent the night in his attic in the inundated Ninth Ward.

As a respite from the sour and stifling air inside the Superdome, the Guard allowed evacuees to go out on the concourse, where it was cooler.

"Fresh air -- it's so wonderful. It's the first time I've wanted to breathe all day," said Robin Smith, 33. "When you think what we could've gone through, it's not too bad in there. But it's certainly not as wonderful as this."

A groan rose from a group listening to a newscast when the devastation was detailed and officials in suburban Jefferson Parish said residents would not be allowed to return until Monday. One woman cried.

"We're doing everything we can to keep these people comfortable," Gen. Ralph Lupin, commander of the National Guard troops at the Superdome, said Tuesday morning. "We're doing our best. It's not getting any better, but we're trying not to let it get any worse."

"I know people want to leave, but they can't leave," he said. "There's three feet of water around the Superdome," turning the signature stadium into the city's Alamo.

Surrounding it was the enemy -- millions of gallons of water from Lake Pontchartrain that flooded most of the city.

Some hospitals that had to close because their emergency generators were in danger of being flooded by rising water sent some of their patients to the Superdome, where four previously hospitalized patients had died, authorities said. Another man died after a plunge from the upper-level seats -- a possible suicide.

Louisiana National Guard troops fashioned a makeshift triage unit on the loading docks of the stadium. Military and civilian doctors rushed from cot to cot, monitoring oxygen levels of storm victims.

Tuesday morning, as water began rising from the breaches in the levee system, emergency personnel worked with soldiers to evacuate the worst of the sick to Baton Rouge. Medical supplies were low, and the dome is not a hospital.

"We've just exhausted our resources," said Keith Carter, the director of Paffard Medical Services. "We need to evacuate."

Lt. Col. Walter Austin, an Army chaplain, rubbed the back of an elderly woman hooked to an oxygen tank, her face twisted in tears. He whispered reassurances.

Since the storm, Austin -- a Catholic wearing a beret adorned with a cross -- had been reassuring the weary refugees at the dome.

"All people are going to be distressed, and the elderly get very distressed when they have a traumatic change in their lives," he said.

That morning, as the floodwater rose, he held a religious service. More than 1,000 people attended.

Out on the loading dock, Jose Mejilla, 45, said he walked several miles from his home to the Superdome, carrying a duffel bag with his only belongings. He slouched as he gratefully devoured an Army meal-ready-to-eat.

"I never thought I would see New Orleans this way," he said in Spanish. "I feel like I'm dead."

Hurricane Katrina damaged the roof of the Louisiana Superdome, which served as an emergency shelter for about 20,000 people in New Orleans. The number of people inside the emergency shelter had doubled since Monday, some having been delivered by rescuers.