Seventeen people were taken to hospital after a balcony collapsed in Dunedin during a concert by the band Six60.
Police said two of the people had "serious" injuries, but not life-threatening. The Southern District Health Board added 17 people were assessed at Dunedin Hospital.
Witnesses have described seeing bloodied, injured people - described by police as "walking wounded" - after the incident this evening.
Students had packed surrounding balconies as the band played a gig near their old flat at 660 Castle St. The concert was played at a courtyard on a private rented flat.
Police estimated approximately 1500 people had gathered in a relatively small area. They, along with Campus Watch, were attempting to clear people from roofs and reduce the people on balconies when the balcony collapsed.
People fell 3m onto the ground and collapsed decking landed on people in the courtyard area below.
A St John ambulance spokesman said four ambulances and a rapid response team were sent to the scene.
Eight people were taken to Dunedin Hospital by ambulance with a range of multiple serious injuries.
Six other patients were taken to hospital with minor to moderate injuries.
Six60 bass player Chris Mac tweeted that the band initially kept playing on advice from police and security, but stopped immediately when asked to do so.
Yes we played the show. But it was on the advice of security and police who we were working with closely
— CHRIS MAC (@chrismacattack) March 4, 2016
.@CrAaronHawkins @odtnews police, security and our team. Once we were asked to sop we did immediately
— CHRIS MAC (@chrismacattack) March 4, 2016
Six60 tweeted that they were very upset that people were hurt and thanked police and security for helping keep people safe.
Very upset that people were hurt tonight. Massive thanks to the local police and security who were working with us to help keep people safe.
— SIX60 (@SIX60) March 4, 2016
A fifth year student who was at the concert described the moment the balcony came down.
"There was probably 15-20 people up there on the balcony. They were just having a good time and all of a sudden it collapsed," he said.
"It landed on about 10 to 12 people."
The student said he looked on in horror as the balcony came down.
"It was like a big crack and then everyone winced ... when you see something like that ... It's one of those things that you never want to see."
He said the crowd's actions in the aftermath of the collapse were admirable.
"The students were helping the ambulance staff. There were a couple of cars in the way and 15-20 guys just lifted the cars, moved them out of the way so the ambulance could get in," he said.
"It was horrific ... there were unconscious people under the balcony ... I saw limbs underneath. But out of respect to them I won't say anymore. It is not something you want to be picturing."
After the balcony came down the band kept playing.
"It happened on the far left [of where they were playing]," he said.
"They didn't realise. As soon as they did realise they cut the music and everyone was out of there."
Jessica Douglas-Withers, a medical student at Otago University, was at the gig. She said suddenly there was a big creak.
Everyone turned around and watched the balcony fall off the side of the building, she said.
As she left she saw three injured people lying on the ground.
Another eyewitness told the New Zealand Herald he saw people leaving the address bleeding from the head and feet.
He said the event was held at 598 Castle St. Up until this year the band held the gig at their old flat, 660 Castle St, but due to limited space they moved it tonight.
"We were there earlier and it was all pretty good, people were having a good time," he said.
"I looked at the balconies and I thought to myself 'if they fill up too much they might collapse as a consequence'."
Witness Rebecca Mercer said some people continued to party afterwards.
"Police tried to break down a fence to make way for emergency services."
Some people were in shock, some had broken limbs, she said.
A witness said the band continued playing after the balcony collapsed.
No commotion could be heard from the stage, and it was only later the band realised what had happened.
About 300 to 400 people were at the concert, the witness said.
One lane is closed on Cumberland St, with emergency services gathering by the Dundas Corner Dairy.
A dairy worker said students had been coming in talking about the incident.
Shopkeeper Jenny Shen said: "Some students came in and said there were many students injured. They saw blood on their faces and it was very serious."
Ms Shen said she could still see three ambulance vehicles, fire trucks and dozens of police officers next to her shop.
"It's still very noisy and there's still some students dancing on the roof. Police are telling them to come down."
Last week police arrested up to 13 people in Dunedin when student parties got out of control.
According to the Dunedin Flat Names website, members of Six60 had moved into the Castle St house with friends from university.
"They had spent time jamming in their rooms and thought it'd be good to flat together and get a band going," the site said.
"They referred to the flat amongst themselves, and to others, as 660, and as the band formed and they started playing shows, they became known as the 660 boys. When it came to releasing their first EP, they decided to call themselves Six60, after that Castle St flat because 'it was a place that meant so much to us'."
At the Hyde Street keg party in March 2012, a roof collapsed under the weight of dozens of revellers.
