One week on, survivors tell of the twists of fate that made the difference between life and death

The Escapes

It was a good day to be late for work. As Ian Robb, a Leeds-born personnel manager for a financial services firm, pushed into the lobby of the north tower of the World Trade Centre on Tuesday morning he was already running half an hour late – it was already past 8.45am. His sense of flustered impatience must have been compounded when he just missed one of the express lifts for the upper floors. Mild exasperation surely mounted to irritated frustration when the elevator he did catch stopped moving almost immediately and lodged in the lift shaft. It was, classically, one of those "why me?" moments.

Speculation has taken us to some strange places in the past week – to the flight deck of a jet plane in which office windows are looming with mesmerising speed, to the boarding gate at which a young man queues quietly alongside the women and children he's about to kill. But it hasn't taken us anywhere quite as insistently as inside those two towers.

As the dust settles some clarity is emerging, including the stark inverted ratio between address and chances of survival – the higher the first, the lower the second.

Stanley Praimnith arrived at his desk in the loan department of Fuji Bank on the 81st floor of the south tower well before 9am. He was sitting there when he saw the first blossom of fire and smoke from the north tower and moved quickly for the lifts. Three floors above him, Brian Clark, who worked at a brokerage firm, heard the announcements assuring tenants that they should remain in their offices and stayed put. Mr Praimnith got out at the 78th floor interchange only to encounter a security guard who assured him that they would be far safer were they were.

Across the plaza in the north tower, nobody could have heard announcements even if they had been made. Dianna Del Fontes was sitting behind the reception desk of the law firm where she worked when the first plane hit, some 10 floors above her. The blast shattered the double doors to the lobby and blew her off her chair. Incredible as this might sound now, the urgency of the situation took time to sink in. With flames just across the hall, Ms Del Fontes closed the door to the firm's conference room to call a friend, changed into the training shoes that so many New York women wear to walk to work, got her backpack and only then joined the mass of people descending the stairs. Just 10 floors below her, Norbert Peat, 42, a technician, had delivered a projector. He waited for a lift back to ground level. As the doors opened, a blast of heat and smoke pushed him across the hall.

Arturo Griffith, a Panamanian, was in a lift at the time of the impact. The whole car shook and juddered as he heard an ominous noise from above

Keith Seagers, an accountant on the 25th floor, was, in theory, much closer to safety and, unlike Ms Del Fontes, he didn't wait to gather his thoughts or his things. He fled.

In the south tower, Lauren Smith, 36, a brokerage employee on the 89th floor, ignored the amplified voices telling people to stay put and took an elevator to the 78th floor – a sky lobby where local lifts met the express elevators to the ground. The security man who had sent Stanley Praimnath back up was either distracted or had changed his mind.

In the north tower, the dust was flying. David Mancano, one of a small army of Brazilian shoeshiners who maintained the executive lustre of the brokers and dealers, said: "We were breathing dirt. It was like eating pure soil." Keith Seagers, trudging down the staircase, was struck by the lack of obvious panic. "I remember how quiet it was," he said, "An eerie silence. I wanted to help those who were finding it harder than me, but didn't really say anything. Nobody said anything. But, as we went down, people were getting more and more nervous. It seemed to be taking for ever and some were clearly worried they wouldn't make it".

Some were already dependent on others. Omar Eduardo Rivera, a blind Colombian, made his way down from 70 floors up, one hand on the shoulder of his boss and the other on the harness of his guide dog.

In the south tower, Stanley Praimnath was on the phone when he looked up suddenly to see the second plane swooping towards the building. He had time to read the writing on its underside before the ceiling split open, dropping rubble and flame into his office. He dived for cover beneath his desk. Three floors above him, Brian Clark raced for the stairs. On the 81st floor, he heard a cry and forced his way through the wreckage to find Mr Praimnath trapped beneath a toppled interior wall. He pulled him out and both men started downwards again.

The huge body blow of the second impact shook loose the elevator car in which Lauren Smith was travelling, causing it to free-fall for several terrifying seconds before the emergency braking system cut in and brought it to a halt. Word travelled quickly on the stairs that a second plane had hit. Just three floors from solid ground and open air, the queue in Ms Del Fontes' staircase suddenly stopped and reversed. Someone panicked, believing the ceiling to be falling in. Only after Ms Del Fontes had been pushed two flights back up was calm restored and the trudge towards safety resumed. When Mr Peat emerged he didn't even notice that the second tower was gone, astounded by the sight of people waving and then jumping from the building he'd just left.

In the stalled lift in which Ian Robb was trapped, routine exasperation had given way to rising alarm as the sprinkler system slowly began to flood it. Those inside prised the doors open to discover that they were still on the ground floor. A fireman told him that the lift he'd just missed had crashed to the bottom of its shaft.

The occupants of the lift used by Lauren Smith were also jemmying open the doors, to discover they were just 7 feet above the polished marble of the lobby. Smith jumped, stumbled and fell into the open lift shaft. She was pulled out by firemen with five broken ribs and a punctured lung but escaped before the building collapsed.

The wave of relief that washed over those who had made it to the ground floor did not last for long. Even before the first collapse, the Plaza was a litter of bodies, debris and twisted steel. Minutes after the first impact Jay Zion, an emergency medical services technician, had arrived at the base of the towers. When the south tower collapsed he, with hundreds of other rescue workers, was suddenly at risk too. He found himself temporarily trapped inside his ambulance and thinking of the most mortal kind of exit. "I just wanted to die quick," he said, "I didn't want to be pinned here for days or have some piece of metal on top of me." The survival instinct revived to enable him to scramble from his crushed vehicle and run several blocks before the second tower came down.

Keith Seagers had set off south but was turned back by a policeman because thick smoke was blowing in that direction too. "Then as I got back to the side of the World Trade Centre there was this huge rumble."

Arturo Griffiths had managed to escape from the tower with a broken kneecap. Astonishingly, some of those inside survived that avalanche of girders and shattered concrete – Ginelle Gusman, who had been on the 64th floor when the plane hit, made it as far as the 13th before the building shivered and dissolved into rubble. She was eventually rescued the following day.

The collapse left the survivors as ghostly versions of themselves. Norbert Peat ran all the way to 37th Street and took a shower at his company's offices to wash off the dust. Dianna Del Fontes, heading northwards too, found herself staring in a shop window at a negative of herself, her black hair and face turned white by dust.

In a stunned reflex of executive etiquette, Mr Praimnath handed his business card to the man who'd saved him.

"Keep in contact," he said. "I owe you my life."