On the bridges into New Orleans yesterday, the traffic was going both ways.
Heading into the city, sheathed in a haze, was a seemingly endless convoy of emergency vehicles and rescue boats, police and military personnel. Heading out of the city was a stream of desperate and bedraggled people - the number of whom seemed equally endless. Some were in cars or packed tightly into the back of trucks; most were on foot, carrying or dragging their belongings, or pushing what they could in shopping carts. It was hot and humid and they looked exhausted.
New Orleans appeared to be a city being pulled in two directions. On the one hand, it was clear the authorities were doing their best to get a grip on the situation - ferrying in supplies, emergency vehicles, flat-bottomed boats and personnel in considerable numbers. At one point, driving in the opposite direction to one convoy, it took minutes for the emergency vehicles to pass.
Likewise, from a vantage point atop the Harvey Canal bridge, I stood and watched helicopters heading into the city, rescue choppers and military aircraft, a constant presence on the skyline.
But alongside these efforts, there were signs the city might be slipping into chaos, a palpable fear among residents and police. Nothing summed this up more than the suspension of the evacuation of people held in the city's Superdome after a shot was reportedly fired at a military helicopter.
"We have suspended operations until they gain control of the Superdome," said Richard Zeuschlag, an ambulance service official.
Reports and second-hand information came in of hotels and hospitals employing armed guards to protect them from looters.
A nurse at one of the city's hospitals for the long-term ill told The Independent: "We heard the hospital next to us was attacked so we have had to have armed guards."
In the Algiers district, directly across the vast and churning Mississippi river from the Superdome, the tension was all too evident. This part of the city had escaped the worst of Katrina's damage, but even here there was no electricity, and the streets were littered with fallen trees, twisted metal and debris. Power lines were down.
The streets were largely empty, but some people roamed around in groups searching for water and food, and for help.
Sitting in his patrol car outside a locked-up chemist's and general store, a police officer said he and his colleagues were desperately trying to keep order. The officer had been working around the clock since the storm struck on Monday morning. His eyes looked red and sore with exhaustion and emotion.
"The stores that have already been hit, I'm not bothering with," he said. "We're not stopping people take food and water... We're just trying to make sure there is a presence here."
As he spoke he picked up a shotgun he had tucked beside him next to the hand-break. "I've brought this from my home," he said. "They've given us nothing from the station."
The officer, who was seven when the notorious Hurricane Betsy struck the city in 1965, confirmed the mounting impression that many people who were stranded in the city had been unable to leave. These people were overwhelmingly poor and black.
"There were some people who did not have the basic means to leave and I blame the city for that," he said.
The officer, who was black, added: "There was no plan. There really should have been a plan for a deal like this. [The ones who could not leave] were poor folks mostly; most are blacks. It's not through any fault of their own [they could not leave]."
Some of the people the officer was talking about were just a few hundred yards away. At the Park Fontaine Apartments, residents without running water or electricity - or, indeed, any hope that things would change quickly - had placed a large white sheet on the floor of their car park. It was a message for any rescue helicopters passing overhead and it said in large black letters: "Need water food."
"There has been no one come round to help us," said Jacqueline Franklin, 44, a recently retired US Army sergeant. "It's terrible. The police are just going past. No one has stopped."
Another resident said their men had been sent out to try to find food and supplies for their children.
Many residents spent the day of the hurricane in a city centre hotel, but were forced to leave as the flood waters rose. They were rescued from one of the city's bridges by helicopter and taken to the Superdome where they had to wade through waist-deep water. From there, they had made their way home.
The residents admitted they had been taking items from any stores they could find, but they insisted they were only taking essentials - food, water and nappies for their children. "The police have let us take the necessities," said Hazel Hollins, 54, a hotel worker.
One emergency official agreed that many so-called "looters" were only taking essentials. Speaking on a local radio station, Tad Troxler, the director of emergency planning for the western suburb of St Charles' parish, said there were "reports from law enforcement of people looting ... stealing beer trucks. But when you hear the stories from these families and they tell you they have just had to get a vehicle to get out of New Orleans, it seems different."
'My pupils' homes were the first to go under'
Diana Boylston, 39, is a teacher in some of New Orleans' sink schools. She escaped, but has been unable to track down any of her pupils:
"My students have the saddest, most heart-wrenching lives. Their parents are on food stamps, lots are on drugs," she said.
"None of their families would have had access to a car or any other means of getting out of the city. The projects they live in were the first to go under. I have tried to instil hope in these kids for so long - but now I'm desperate. I think they are dead.
"Two of them, Dwight and Dwan, are twins who I am very close to. I called them on Monday morning at about 4am to try to persuade their mother to take them to the Superdome. But she was out. Their neighbour explained she was going to make them 'stick it out' as God was on their side and wouldn't let anything bad happen.
"I spoke to them again on Monday morning, just a few hours after the storm hit, but I have heard nothing since. I am so worried. Their homes would have been the first to go under.
"People in the poor, black-dominated projects have suffered the most."Reuse content