"We are a smaller school and it's definitely had a widespread impact on students - not only her close friends but also the wider student circle and staff."
She had returned to school after the summer break with a renewed focus on her studies.
"Like any other teenager she's had her ups and downs. But this year she found a new lease on life, she had a real focus on her school work. She matured over the school holidays, she was moving forward and she wanted to make a difference. That sadly was taken away from her this morning."
Mr de Villiers and an assistant principal met with her family yesterday morning.
"They are obviously extremely distraught and obviously didn't have any sleep [on Wednesday] night."
The incident had happened "just around the corner" from the family's home, which was also "very close" to the school.
Miss Thorner had been at the school for three years and her older sister was in year 13.
The Palmerston North rescue helicopter was called to Dannevirke to transport her from the scene of the incident but wasn't needed, pilot Chris Moody said. She had been reported to have serious head injuries.
"We were called because of the time-critical nature of the girl's injuries, but sadly she'd died prior to the airlift."
Police wanted to hear from anyone who may have been in the area of King and Edward Streets in Dannevirke about 9pm Wednesday night.
* If you know something relevant to this investigation please contact Detective Sergeant Oram on (06)3513600. Alternatively information can be provided anonymously via Crime stoppers on 0800 555 111.