A 12-year old girl collapsed and died in her father's arms – after suffering months of torment by bullies at school.
Holly Stuckey's sudden death is being investigated by police and educational officials, as doctors have still not explained the cause.
Her grieving dad, Clive, who said she was complaining of chest pains before she died, believes that bullies at her school may have put a strain on her heart.
'People made fun of her because she did not know much about sex education,' he said.
'She was a beautifully innocent young girl but the kids turned on her and started to call her a lesbian because she didn't know as much as them.'
'In the weeks before Holly died, she wouldn't go anywhere on her own. She wanted me to take her everywhere.'
Clive described how, after her death, he found letters in her bedroom which referred to the fact that she was being bullied by other children. One note read: 'I hate you for what you've done. I feel like no one.'
Holly was an only child who lived near Brigend, South Wales, with her dad Clive and mum, Lee. She attended nearby Maesteg Comprehensive School.
Clive said: 'Holly was withdrawn when she came home from school – she only had three friends. The rest turned on her. But her confidence would come rushing back when she came into the house. She was always singing and dancing around, or playing on her Wii.'
He has given the names of 13 children to police investigators. Although Holly suffered from asthma, it was thought to be under control, and a post-mortem was inconclusive.
An inquest has been opened, but her parents have been told that it may be three months before they discover what caused her death. 'We just don't know, but it could have been the emotional strain of what she was going through which brought on a heart attack,' said Clive.
'I have been contacted by several other parents who have told me that their children are being bullied. I want other parents to stand up for their children. I want to protect them.'
A school spokesman said: ' We employ a zero-tolerance approach to bullying and offer quick action to support victims, deal with bullies and resolve any conflicts.
'If any pupil is found to have been involved in bullying, their parents are informed and are asked to attend a meeting along with their child, where the school's position is made very clear. Appropriate action is taken as required.'
Holly's funeral was held at the Church of St Michael in All Angels, in Maesteg. Her body was carried in a Hannah Montana coffin. Her parents paid tribute to her daughter during the service, saying: 'You brought sunlight in our lives. The angels will look after you now.'