I was at work in an office building on Euston Road (about 3km away) when the attack happened.
We play the BBC in reception and a lot of people were gathering around watching the news, some calling family, others saying they just wanted to leave work to be with their kids.
On my way home I could hear heaps of sirens and there were about a dozen machine gun-laden police officers at my train station (St Pancras).
No-one seemed exactly surprised, which is pretty sad.
It's well publicised here that the authorities are constantly on high alert for this sort of attack.
Like any random misfortune, you just hope you aren't in the wrong place at the wrong time.
I've only been here two weeks and the city doesn't seem scary or sinister because of what's happened today.
If anything, it was the warmest I've seen London so far: strangers reassuring each other on the train, people on the phone to their families saying they loved them, and lots of civil servants going into high gear trying to keep people safe.