The drama unfolded as a party at a holiday home apparently spiralled out of control. The Medbury Tce property in Fendalton can be hired for up to eight people - but scores more turned up.
Detective Inspector Scott Anderson said in a statement this afternoon: "Police extend our sympathies to his whānau, and we are providing them with support alongside Victim Support."
A post-mortem examination has been completed today, Anderson said.
"Officers continue to carry out a number of inquiries to establish the circumstances of this incident, including identifying and speaking to those in the area at the time," Anderson said.
"The scene examination on Medbury Tce is ongoing, and we thank neighbouring residents for their continued cooperation and understanding as officers carry out the important work of collecting evidence and canvassing for witnesses and information.
"Police are determined to locate the person or people responsible for this senseless incident, and we continue to urge anyone with information or CCTV footage that can help police to get in touch."
A woman whose daughter was at the party told the Herald the attack was instigated by a "young boy" who caused a fight after he was turned away from the property.
The mother said she was not entirely sure what had happened to then lead to the stabbing because her daughter was finding it difficult to speak about the ordeal.
However, she believed some boys milling outside the house were ambushed by others "waiting in the dark".
"The young boys had no idea what was about to happen," the mother said.
Anderson said police had not arrested anyone but wanted to talk to everyone who was at the party - and he urged them to come forward with information and call 105 quoting "operation Medbury".
Anderson said police know photos and video of the party will be out there to assist their inquiries - and are seeking them.
"Our staff arrived to find three young men aged 17, 16 and 14 with serious stab wounds. They were taken to Christchurch Hospital where the 16-year-old has sadly died. Two others are in a serious but stable condition," Anderson said.
"It is believed there were in excess of 80 people at the party, and they were predominantly young people.
He confirmed the property where the stabbing occurred was a holiday home that had been rented. Police had talked to the person who made the booking but had not yet been able to speak to the two teen victims in hospital.
"Their health's more important at the moment than us talking to them," Anderson said.