Karen Rowland assumed, like so many others, that the first plane was an accident when she saw it on TV.

Accidents like it had happened in New York City before. It must have been like when a plane crashed into the Empire State Building in 1945.

Leaving her flat, still alarmed by what she saw, she met a neighbour, a doctor who worked at a nearby hospital, St Vincent’s. She told him he would have a “rough day”.

Moments later, having left their building, she saw the second plane hit the World Trade Center. She realised what was happening around them was no accident.

“There was screaming and hugging of total strangers and a lot of silence,” she said.

“In a moment like that you don’t really grasp what’s going on. Later I came to find out that I knew people on that plane. They were buyers of mine.”

Then a fashion designer in New York, she now lives in Reading and is a former borough councillor.

She said she was changed forever by what she saw that day and the days that followed.

“It started as one of the most beautiful days,” she said. “To this day when there’s a beautiful, perfect day I still say it’s a 9/11 day.

“It was the day that changed my life. I have a before 9/11 life and an after 9/11 life.

“It changed the way I think I relate to people, how we all have to look after each other a bit more.”

Illnesses related to the dust and smoke from the towers’ collapse have claimed more lives than the nearly 3,000 who died in the attacks on the city, US health officials have said.

Another 184 people died in the attacks at the Pentagon in Virginia and 40 on Flight 93, where passengers overpowered hijackers.

“[The days after were] very difficult. It was very eery. The smell stayed for days and that will never come across on a video or anything like that,” Rowland said.

“There was a smoke ring that hung around for days. It was just dead silent for days.

“Mobile [phone] services were restored and we were able to get in touch with each other, to find out and check and make sure that everyone we knew were alive.

“Signage was going up: ‘Have you seen this person? Have you seen this person?'”

Yet looking back on the day when her city and the world changed, she remembers how she had been asked by her doctor neighbour to organise people who had gone to St Vincent’s to donate blood.

“The fact was the emergency room wasn’t busy that day; it was just busy with people trying to volunteer. There were no survivors that were coming,” Rowland said.

“We were the closest hospital to the site but there were no people coming in.”