A school principal told today of the profound sense of shock after an " intelligent and lively" pupil was found dead on her 15th birthday.
A post-mortem was being held today to find out what caused the death of Naomi Wilson, from Dromore, Co Down.
Principal of Dromore High School, John Wilkinson, this morning led warm tributes to Naomi, who was found dead at her home in the town at 9am yesterday.
The youngster's family were left devastated on the day they should have been celebrating her 15th birthday.
Ahead of today's post-mortem examination, the cause of death had not been established.
Mr Wilkinson said the school had been left "numb and shocked" by the Year 11 pupil's sudden death.
"This school has lost one of the most lively and trustworthy young people. She was engaged to full in the life of the school and she was well-liked by all," he said.
The head teacher said the teenager had a particular interest in stock car racing "which she enjoyed with all members of her family".
"Naomi was in the top band of her year, she was an intelligent girl. The whole school was left numb and shocked when news of Naomi's death came through yesterday.
"We held two special assemblies in her memory," he added.
"Her classmates are particularly shocked. We have a counselling system in place to help them deal with this.
"The school also remained open last night with senior teachers here to provide support to any parents or pupils in need of it.
"We will be doing the same again tonight."
An ambulance crew and doctor were called to Naomi's home on the Maypole Road in Dromore yesterday morning. It is understood the schoolgirl was pronounced dead at the scene.
Young Naomi is survived by her father David Wilson, mother Belinda Orr and brother Jonathan.
A family death notice placed in today's Belfast Telegraph described Naomi as the "light of our lives".
"You shone like the brightest star in the sky. Your lovely smile and big brown eyes will always be with us," it reads. "We all love you so much and will miss you forever."
It said she will also be remembered with love by her father's partner Roma, sister-in-law Nikella, nephew Jake, niece Natasha and the entire family circle.
Chairman of Banbridge District Council, John Hanna, also paid tribute to Naomi.
"My personal sympathy and that of the council goes out to the family," he said. The funeral is scheduled to be held at Dromore Cathedral on Friday afternoon and she is due to be buried afterwards in Dromore Cemetery.