However, the coroner did not believe that the girl intended to end her life.
"Quite possibly all she was motivated by was ending her distress, not ending her life," the findings state.
"The circumstances of this case were, on any view of it, among the most confronting and upsetting as anyone might expect to encounter in what appeared to have been a typical day at a New Zealand primary school," Coroner na Nagara said.
The coroner found nothing about the events that struck her as being unusual or cause for concern and stressed that she had no criticism of any of the staff at the school.
"Her death was an abject tragedy, and her passing has been devastating for her family, friends, and her school community," she said.
"I extend my heartfelt sympathy to all those who knew and loved her, and most particularly to her family who have suffered an unthinkable loss."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.