BELFAST, Northern Ireland — It was a scene that showed how far Northern Ireland has come, and how far it still has to go.
Inside St. Anne’s in Belfast, a Protestant cathedral, the life of a young woman from a Catholic background was celebrated on Wednesday afternoon by leading politicians not just from across Northern Ireland’s divided political spectrum, but from across the Irish Sea.
The leaders of the area’s largest nationalist and unionist parties, Arlene Foster and Mary Lou McDonald, sat side by side, just a few yards from Britain’s prime minister and opposition leader, Theresa May and Jeremy Corbyn, and Ireland’s president and prime minister, Michael D. Higgins and Leo Varadkar.
Despite their profoundly different views on how Northern Ireland should be run, on the concept of a unified Ireland and on Brexit, all of them had gathered in a packed St. Anne’s to mourn the death of Lyra McKee, a 29-year-old journalist shot dead last Thursday by militant nationalists in Londonderry, Northern Ireland’s second city.
“Since Thursday night, we have seen the coming together of so many people in various places and the unifying of the community against violence,” the Rev. Martin Magill, a Catholic priest, said in a eulogy during the service. Like many, he marveled at the unlikely juxtaposition of leaders who, during Ms. McKee’s own childhood, would never have been seen in the same room together.
“I am, however, left with a question,” Father Magill added a moment later. “Why, in God’s name, does it take the death of a 29-year-old woman, with her whole life in front of her …”
He could not even finish his sentence. The mourners, both the 1,000 gathered inside and the hundreds standing outside in the cold, had begun to applaud.
Then they began to stand. First those at the back, and then those in the middle, before, finally, the politicians at the front — some stone-faced, one or two almost tearful.
And there they remained until, what seemed like minutes later, Father Magill finished his sentence.
“… the death of a 29-year-old woman, with her whole life in front of her,” he continued, “to get us to this point?”
By many measures, Northern Ireland has made remarkable progress since the formal end in 1998 of three decades of conflict between nationalists, drawn mainly from Catholic backgrounds, who want to unite Northern Ireland with the Republic of Ireland; unionists, drawn mainly from Protestant backgrounds, who want to remain part of Britain; and the British state itself.
The region has mostly been governed, through a power-sharing agreement, by a coalition of nationalists and unionists. The region’s main militant force, the Provisional Irish Republican Army, gave up its weapons in 2005. And border crossings between Northern Ireland and the Republic of Ireland have been removed, making it easier for people on either side to live lives that span both territories.
Yet in recent years Northern Ireland has begun to drift.
The power-sharing agreement has collapsed because of disagreements between Ms. Foster’s and Ms. McDonald’s respective parties. For more than two years, the impasse has left Northern Ireland in the hands of civil servants, who have avoided making significant political and financial decisions.
Riots broke out in Londonderry after the police raided a home in a nationalist area of the city last Thursday evening. Amid the melee, a masked militant from the New I.R.A. fired at least four shots toward a police van.
The next day — the 21st anniversary of the Good Friday Agreement, as the 1998 peace deal is known — Northern Ireland awoke to learn that one of those shots had hit Ms. McKee by accident.
Her death seemed to jolt the region from its stasis.
Unionist and nationalist leaders issued joint statements of condemnation, and made joint appearances in Londonderry. They made encouraging noises about restarting power-sharing talks. Even dissident republicans, or those who feel the nationalist leadership has made too many compromises, joined in the criticism of the New I.R.A.
On the ground in Londonderry, residents painted over I.R.A. graffiti and smeared red paint on the office of a political party linked to the militants.
“Not in our name,” reads a new addition to the most famous republican mural in the city. “R.I.P. Lyra.”
Ms. McKee’s death struck such a chord not just because of when it happened, but for who she was.
Ms. McKee was “a child of the Good Friday Agreement,” the dean of St. Anne’s, Stephen Forde, said on Wednesday — because of both when she came of age, and the way she lived her life.
“My generation sang about an alternative Ulster,” her friend Stephen Lusty said in another speech on Wednesday, referring to the Irish province in which Northern Ireland is situated. “Lyra lived it.”
Born on the edge of one of the most dangerous areas in Northern Ireland, Ms. McKee was named just 25 years later as one of Europe’s most influential young journalists by Forbes magazine.
She won widespread acclaim in 2014 for an online essay about her experiences as a gay teenager in conservative Belfast society.
Ms. McKee had already written one book of nonfiction, about a unionist lawmaker murdered in 1981 by republican militants, and had been contracted to write two more, including an investigation into the disappearances of young men in Belfast during the 1970s.
Her own death during Easter week served as a brutal reminder of that kind of violence.
But it may also prove, Father Magill said, to be a galvanizing force against its recurrence in the future.
“I dare to hope,” he said, “that Lyra’s murder on Holy Thursday evening can be a doorway to a new beginning.”