A journalist shot dead by dissident republicans in Londonderry was a person of courage and integrity, her colleagues said.
Belfast-born Lyra McKee, 29, was a published author with a promising career ahead of her, the National Union of Journalists (NUJ) added.
The Irish president and political leaders were among those paying tribute to a talented and committed young writer.
Michelle Stanistreet, NUJ general secretary, said: “A young, vibrant life has been destroyed in a senseless act of violence.
“Our thoughts are with her partner, family and many friends and colleagues. A bright light has been quenched and that plunges all of us in to darkness.”
For many people, their first introduction to her work was her piece about growing up gay in Belfast – Letter To My 14 Year-Old Self – which was subsequently turned into a powerful short film, the union said.
Angels With Blue Faces, a non-fiction book about the Troubles murder of South Belfast MP Rev Robert Bradford, was released in 2018.
Faber is due to publish her book, The Lost Boys, in 2020.
Seamus Dooley, NUJ assistant general secretary, said: “Lyra McKee was a journalist of courage, style and integrity.
“She was a woman of great commitment and passion.
“I have no doubt that it was that commitment which led to her presence on the streets of the Creggan last night, observing a riot situation in the city.”
She had worked for the Belfast Telegraph newspaper as well as a range of other publications.
Irish President Michael D Higgins said: “The people of Ireland will have heard with both shock, outrage and great sadness of the killing of the young journalist Lyra McKee in Derry last evening – a woman of talent and commitment, who was shot exercising her profession.”
Ann Travers, whose sister Mary was murdered by the IRA in 1984, said Ms McKee was a kind and gifted person.
Irish deputy premier Simon Coveney said it was a shocking and tragic death.
He said: “As we mark the 21st anniversary of the Good Friday Agreement, we are reminded that the vast majority of people of this island voted overwhelmingly for peace and reconciliation and an end to violence.
“There can be no going back to those awful days.”
Amnesty International said it was “utterly devastated” by the death of Ms McKee, who was to appear at one of its events in Belfast next month about the dangers of reporting violent conflicts.
Patrick Corrigan, Northern Ireland programme director of Amnesty International, said: “Lyra was a great young journalist, whose commitment to truth was absolute and whose laughter could light up a room.
“Lyra McKee was one of those courageous seekers after truth, with a life ahead of her and so much to give.
“Our thoughts are with Lyra’s partner, her family and many friends.”
The Society of Editors also added its voice to those condemning the shooting.
Ian Murray, the Society’s Executive Director, said: “Lyra was a tremendous talent and the journalistic world has lost one of its bright hopes for the future.
“The death of anyone under such circumstances is to be roundly condemned, but for those of us working in the media it is terrible to lose such a fantastic colleague.”