On the 5 live blog station controller Adrian Van-Klaveren has written a post detailing 5 live's coverage of the tenth anniversary of 9/11. He recalls where he was at the time (as I'm sure we've all done in the last few days):
At the time I was Head of BBC Newsgathering. I remember catching up with the breakfast news and then setting off for some meetings at the BBC's Washington office. It seemed an entirely unremarkable news day. After 15 minutes walk, I arrived in the office to find an extraordinary amount of activity for that time of the morning. The first plane had struck the Twin Towers.
Within the coverage Peter Allen and Stephen Nolan will be reporting and presenting from the United States, including special programmes from Florida where President Bush heard the news and Victoria Derbyshire will have rare access to Guantanamo Bay Detention Camp, presenting her Friday programme from there. You can find more details and leave a comment on the 5 live blog.
On Monday night Radio 1's Mike Davies presented a musical history of 9/11 and its aftermath, featuring interviews, archive and the sounds of the likes of Moby, My Chemical Romance and the Beastie Boys.
Radio 2 marks the anniversary with Faith and 9/11. Journalist and Pause For Thought contributor, Abdul-Rehman Malik guides listeners through a reflective anthology combining personal reflections - past and present - with news archive including an interview given to the BBC by the Archbishop Of Canterbury, Rowan Williams, shortly after the terrorist attacks.
A Guernica for Gotham on Radio 3 investigates how New York artists have responded to the destruction of the Twin Towers. Interviewees include composer Steve Reich and writer Meg Wolitzer.
Radio 4 is currently broadcasting the second half of this year's Reith Lectures under the title Securing Freedom and you can download the first of Eliza Manningham-Buller's lectures, Terror, from the website.
There are details of Radio 4's other coverage on this page 9/11 - Ten Years On including The Saturday Play Washington, 9/11 and The Day before 9/11, a portrait of New York, America and the wider world as it was - the day before.
Gwyneth Williams, the controller of Radio 4, has written about Radio 4's coverage of 9/11 on the blog, where you can find out more and leave a comment.
Paul Murphy is editor of the Radio blog