9/11 four years on: 'I can't escape the nightmare of the planes slamming in'

As America prepares to remember, one British survivor of the attack on the twin towers says she will never be able to forget

"As the day approaches I get nervous and twitchy," says the British survivor, who still lives in New York. "I don't sleep, mainly because I have terrible nightmares. They're so vivid that I can almost reach out and touch the people. I wake up in tears and I know that if I go back to sleep I will pick up exactly where I left off, so I don't even try. I get up and do my laundry or walk the dog. It's amazing how many people you meet at three in the morning."

Janice had just picked up the phone when the first plane slammed into the north tower of the World Trade Center four years ago. She was working as a secretary for the financial firm Euro Brokers on the 84th floor of the south tower, having only just transferred to the company's New York office the week before.

There was a loud bang, her computer screen flickered and paper filled the air like confetti. Before heading for the stairs, she called the London office, explaining they were evacuating the building as something was happening in the other tower. The reply shook her: "Something's happened next door? Hell Janice, a plane's gone into the building - get the fuck out of there."

When she and her colleagues reached the 72nd floor, security officers announced that the tower was secure and workers were to return to their offices. For 10 minutes they climbed back up the stairs. Suddenly, there was a dull thud, as the second plane struck. The building shook and the ceiling fell down.

"I heard a woman's blood-curdling, high-pitched scream and a man shouting for help," says Janice, 45, from Brentwood, Essex. One man pulled open a door and six shocked and bloodied people staggered through. "The first woman had blood all over her arm, which was cut, almost neatly, from her shoulder to her elbow. I remember seeing the bone and the skin just flapping around," says Janice. Another woman, her eye full of blood, was screaming that she couldn't see.

The stairs which the group had just walked up were no longer there. They started to descend another staircase. "I went on automatic pilot and just did what I was told," says the secretary, who walked behind the woman with the injured arm. "I remember looking down at my left foot and seeing blood oozing through my bare toes as I stepped behind her." When they got out of the building, Janice looked behind her to see a gaping hole where her floor had been.

In all, 61 Euro Brokers staff died. Janice had worked for the company for 11 years and knew many of the victims. Over the next two months, she went to 20 funerals. "Some days we went to two." Euro Brokers found new office space and Janice returned to work.

"I had my dad on the phone telling me to come home, but I decided to stay," she explains. "The feeling of solidarity was amazing. I thought the understanding and support I would get here would be far greater than in London." She started counselling, which helped. "I don't think I will ever understand it. I will spend my life trying to find some peace and understanding, but I don't think I will ever get that."

Euro Brokers has now been sold and Janice plans to return to the UK. She will spend the anniversary quietly at her apartment in Queens, watching the commemoration on television during which the names of the victims are read. In the evening, she will go to Ground Zero and say a prayer for the friends she lost. Then hopefully her nightmares will be over for another year.