Partygoers frantically tried to pull people out of a pile of bodies after they were crushed in a stairwell at a Dunedin house party.
One woman died and two others were seriously injured after the incident at a Dundas St flat, known as The Manor, on Saturday night.
A witness, who declined to be named, said they were about halfway up the internal stairs when people coming down started pushing into each other, with a "massive crowd" of people going up.
"They started to fall backwards and when the people at the top started falling it was kind of like dominoes – everyone went down and the people at the bottom of the stairs just ended up in a pile of people," the witness said.
"I was trying to hold it up, I could see it getting bad, then I started to get knocked over, got out of the way. I'm a heavy person, if I get anyone underneath me it wouldn't be good for them."
He then made his way out the front door, with about 50 people in a pile outside the front door. He said the pile was about 1 metre high.
The student, with the help of about 15 others, tried frantically to pull everyone out of the pile, however more people kept coming down the stairs trying to force their way out, making the pile-up worse.
"We would get people off and more people would end up getting pushed back on top of the pile."
By the time police arrived the group had managed to clear most of the pile, aside from a few people lying on the ground unconscious.
He said the woman who died was found at the bottom of the pile, and was one of the last people to get out.
"I just thought she was unconscious like everyone else."
Several people carried the woman from the ground floor down the stairs and across the road where ambulance staff tried to resuscitate her.
The witness said he was angry with fellow partygoers, who he said made the situation worse.
"The whole time people were more interested in trying to force their way into the front door where everyone was getting crushed, we were trying to pull people up and people were trying to force their way in.
"People were struggling and instead of helping people were way more interested in trying to party."
Another student, a first year, said the party started to get big about midnight. People heard a rumour security was coming and there was a rush for the front entrance, he said.
"A lot of people [were] coming in and out and it started to get quite built up by the door, and people started falling over ... we were trying to get people out, people that were on top of the pile, we were trying to pull them out but there were too many."
He said he tried to help people that were suffocating. "You could feel their body temperature, [it was] just hot as."
He helped bring the woman out of the party and learned she had died. He dropped flowers off at the site on Sunday "to pay his respects", he said.
Another student, who had visited the student flat several times said it was the "most out of control party" he had ever seen there.
"It's traditionally a party flat, they have a couple during the year, but this one was next level."
He and his friends were partying in a room inside the house when they heard what sounded like people tumbling down the stairs. A short while later he got a call from a friend to say someone had died.
He then went outside and saw the area "crawling with cops", with several ambulances and firefighters.
On Sunday morning, glass littered the street outside, along with seven individual shoes.
The property was cordoned off, with two security guards stationed outside the house. Officers could be seen walking up the stairs inside the property. Flowers were placed outside the house.
A Dunedin student told Stuff the party was to be the last held at the flat before the University took it over next year.
A University of Otago spokeswoman confirmed it would lease the building next year and would review what the building would be used for over the coming weeks.
University of Otago's vice-chancellor professor Harlene Hayne said the university was working with those affected and police.
"We are deeply saddened by what occurred last night. We are supporting the family of the student who died. Many members of the student community are badly affected by what occurred last night. Our staff are working with them today, and will continue to do so, at this very difficult time," she said.
The university would work with police as the investigation progresses, she said.
Otago coastal police area commander Inspector Marty Gray said the incident happened around midnight.
"Ambulance and police were called to a Dundas St property just before midnight after the occupants had called for assistance to shut down a party," Gray said.
"On police arrival, a large number of people were in the process of leaving the property, and there were reports of people being injured as they did so.
"If you were at the party and have not spoken to police, we would ask you to please get in touch, to help us piece together what happened."
Victim Support is available for those who were present, police said.
The all-male flat is two blocks away from Castle St North, where a balcony collapsed during a secret concert on March 4, 2016.
