Do you remember where you were on 9/11? Share your memories 25 years on

Twenty-five years ago this Friday, four hijacked planes changed the course of modern history.

Almost 3,000 people were killed when the World Trade Center's twin towers collapsed in New York, the Pentagon was struck in Washington DC, and a fourth plane came down in a field in Pennsylvania after passengers fought back against the hijackers.

For anyone old enough to remember it, 11 September 2001 is one of those rare days that stops time – the kind people can recall in minute detail, down to what they were wearing or the programme that was interrupted on television.

A quarter of a century on, the attacks still shape global politics, security and travel in ways many of us barely notice. But for those who lived through that day, the memory of where they were when they first heard the news has never really faded.

So we want to hear from you. Where were you on the morning of 9/11? Were you at school, at work, on your way somewhere else entirely? Do you remember who told you, or how the day unfolded from there? And looking back 25 years later, how do you think that day changed things – for the world, or for you personally?

Share your memories in the comments below, and we'll feature a selection of them in a piece marking the anniversary this Friday.