When the attack on Westminster started to unfold, my work office was put on lockdown. Staff were briefed on the situation outside and we were advised to stay away from the windows until we knew exactly what was going on. In the uncertainty, many of us sent messages to loved ones to say we were safe.
As details emerged of the situation on Westminster Bridge and Parliament Square - less than half a mile from my office - we soon knew that we weren't in danger. But on leaving work that evening, the air full of sirens and helicopters, I think everyone in Westminster felt in some way afraid.
Growing up in Belfast I've often heard about the hyper awareness that comes with being in a place where there's terrorism. In the years after the IRA campaign, many people in Belfast still checked beneath their cars for bombs before getting in them. On leaving Westminster last Wednesday, my hyper awareness was for the cars on the road that could be weaponised. In my unease, I rushed across Vauxhall Bridge to the train station because, in my head, if anything else were to happen it would be on another bridge.
In the immediacy of terrorism, it does exactly what it is meant to do. It brings fear and irrational nervousness. In these moments, you almost feel beaten for letting yourself be rattled because that's what the terrorists want. But as security is reestablished and find your way home safely, a fire of defiance soon kicks in.
In the days since the attack, London has shown it's steel heart of resilience. At the vigil in Trafalgar Square, Sadiq Khan summed up London's message to the world: "We will not be cowed by terrorism".
Defiance will be needed in the weeks after the attack, not just against terrorism, but against those who now will target London's values of diversity. Hours after the events in Westminster, Nigel Farage attacked Britain's immigration policy and blamed London's multiculturalism for opening the door to extremism.
It's this kind of rhetoric which demands real condemnation. In today's global climate, where referendums result in borders and presidents are building walls, division is by no means an abstract concept. The world is in a state of separation and fearmongering narratives are often to blame. They pit communities against each other and ultimately create hate.
It's important, now more than ever, to defy the rhetoric of division, to challenge islamophobia and racism, and stand for the global message of building bridges, not walls.
Fortunately, London is a proud city of bridge builders. Amazingly diverse, tolerant and resilient, London welcomes the many different racial and religious communities that live here. And even while it's bridges and values are under attack, their structures will always remain standing.
Less than 24 hours after the attack, Westminster bridge reopened once again. I walked across the bridge and felt a surprising sense of normality. Tourists turned up for selfies, buses continued on their everyday routes and office workers still made their lunch time walks. And while those who were lost in this attack will never be forgotten, London has proved that it will continue embodying the values which make it so special. In the face of fear and shaken security, London will continue to build its bridges and walk them every day.