It was the perfect New York autumn morning. The kind of bright sun, cloudless sky and cool breeze that only exists in the movies.

A young red-headed attorney in his late 20s, wearing a crisp white shirt and a red tie, sipped his coffee as he made his way to work. Just blocks from the twin towers of the World Trade Center, he heard a plane overhead. It sounded too close. He looked up and saw a Boeing 767 jetliner crash into the World Trade Center's north tower. Moments later, he saw three bodies fall from the sky.

Rush-hour traffic weaved smoothly through midtown Manhattan, Times Square and down the West Side Highway that lines the western axis of the island of Manhattan. Taxis worked their way south, toward Manhattan's financial district, when congestion began to tighten.

Cars were forced to pull over to make room for the blaring sirens of ambulances and unmarked police cars, which buzzed in pairs through the streets of the neighbourhood of Chelsea at 23rd Street before shooting off in separate directions.

Within a half-hour of the attacks, the smell of burning metal had made its way uptown.

New Yorkers, unflappable but curious, began to congregate on street corners. Mothers with baby strollers, businessmen, students, construction workers, waiters and bicycle messengers pointed to the sky, where flames licked the shiny surface of the World Trade Center towers. Puffs of light black smoke hovered above.

Downtown, police officers and FBI agents barricaded a six-block radius, while hundreds of spectators began to gather.

Thousands of others streamed toward safety, pausing to watch the towers burn, stunned but calm, and eerily quiet. Dozens of people lined up wherever a public telephone could be found, while others tried futilely to use their mobile phones.

A policeman urged onlookers to keep moving. "These building aren't stable. There might be more bombs, there might be nerve gas. Let's go," he said. The mass exodus was slow. No one believed it could get any worse.

A young black woman supported an elderly white woman in tears. Their clothes had been soaked by their building's sprinkler system - evidence that they had been in one of the doomed towers.

Then, a thunderous boom.

The south tower began to crumble. Like an avalanche, a cloud of dark grey smoke and debris hurdled down the streets. Screams and a stampede were instantly replaced by white-grey smoke and the sounds of people choking on dust and gases.

A few blocks away, evacuees gasped in unison as the south tower crashed to the ground. One woman inched back in disbelief, shrieking while clutching her head. Then instinct took hold. She turned and bolted in an attempt to outrun the oncoming cloud.

A policeman urged people to stay calm, to walk, to find shelter - but where?

Shopkeepers kept their doors locked, while those caught in the storm banged furiously for help.

One music store allowed 15 people into its basement, where they lined up to wash dust from their eyes.

Inside, two tourists whispered in Dutch, while a Chinese man smiled nervously and motioned he was in need of a tissue. Secretaries sat in the stairwell, one weeping on the other's shoulder.

Three stores away, a deli owner unlocked his doors to emergency workers blinded by dust. A young hispanic man tried to slip in behind them. After initially refusing, the deli owner let him in, gave him water and offered him a telephone.

Outside, a solemn, broad-shouldered police sergeant - commanding respect in his dark blue uniform, gold star and hat - stood with his men along the street in relative safety.

The first tower had fallen about 25 minutes earlier. Then another thunderous vibration.

"What the f..k was that? What the f..k was that?" the sergeant asked, fearing there had been another attack as he turned his head to the sky.

Silence and then mumblings from a hand-held radio: "The second tower is down." New York's majestic skyline was destroyed.

A black man in his mid-50s and wearing a white suit walked from the destroyed area. He was in such shock that he did not bother to brush the pile of soot from atop his head, shoulders and briefcase. Dust was caked on his skin, thick as clay, and tears streamed down his face, leaving streaks of exposed skin.

Blocks away from the chaos, a small group of strangers gathered around a parked black Mercedes-Benz car with open windows trying to hear the latest news on the radio. The Pentagon had been hit and it became apparent that the havoc and chaos would not stop at New York.