Teenage boy Oisin McGrath has died after he was grievously injured during a school playground incident.
Oisin (13) was a pupil at St Michael's College in Enniskillen, Co Fermanagh, and was hurt while playing football during his lunch break on Monday afternoon.
A 17-year-old boy was arrested and later bailed pending further police inquiries into what happened.
First Minister Peter Robinson tweeted: "Young Oisin McGrath's death is heartbreaking.
"I'll be praying for his family and all those devastated by this sad news tonight."
The Belfast Trust confirmed his death shortly before 7.30pm last night.
Fr Seamus Quinn had been at the victim's bedside.
He said: "People were shocked when they heard that there were no signs of life and the support would be gradually removed."
Oisin, a keen Gaelic footballer from the village of Belcoo in Fermanagh on Northern Ireland's western border with the Republic of Ireland, was treated in the Royal Victoria Hospital (RVH) in Belfast.
St Michael's is a Catholic boys' grammar school with 700 pupils.
Fr Quinn said Oisin was a very well-grounded and well-rounded young teenager.
"He was happy and helpful, genuinely helpful, intelligent young fella.
"They are a well-loved and well-respected family, they are solid, salt of the earth people, faith-based people, Christian people."
He said the community in Belcoo had been united in prayer for Oisin, with 500 people attending Catholic Mass on Wednesday night at St Patrick's Church in Holywell - a small village outside Belcoo.
"There is a silence in the village, there was a silence after Mass last night, naturally people were just dumbfounded and in shock.
"For anybody who has children it is their worst nightmare."
The teenager played Gaelic Athletic Association (GAA) football in Belcoo. His mother Sharon is secretary in the local club.
The school said: "A group of students were playing at lunchtime when one student became unwell and we sought medical assistance."