There were multiple injuries after a balcony collapsed at Six60 gig in Dunedin.

The collapse of a Dunedin balcony was because of overloading, a Dunedin City Council report says.

Eighteen people were injured when a balcony collapsed during a surprise Six60 concert in Castle St, Dunedin on March 4.

Two people were seriously injured, including Bailley Unahi who suffered spinal injuries and remains in Christchurch's Burwood Hospital.

RILEY BAKER/SUPPLIED Police and bystanders rush to help after a balcony collapsed at a surprise Six60 concert in Dunedin.

A structural engineer investigated the balcony collapse on behalf of the Dunedin City Council, and concluded it was "critically overloaded beyond its ultimate capacity", general manager services and development Simon Pickford said.



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The report

Pickford said he stood by the council commissioned report as "a good piece of work".

SUPPLIED Bailley Unahi, 19, suffered serious spinal injuries after a balcony fell on her at a Dunedin Six60 concert.

"We set out to get an independent view of what happened . . . . and it does confirm what we originally thought, but goes beyond that and suggests some ways in how we can make these things safer".

The report helped reassure the owners of the Castle St complex that "the properties they have are safe under the current code".

When asked about issues of culpability, he questioned the decision in having "an event like that".

RILEY BAKER/SUPPLIED The balcony fell about 3 metres during a surprise Six60 concert in Dunedin.

"If proper risk management had been done by the organisers then the tragedy could have been avoided."

The question of culpability was not a role for council, but "more work needed to be done to find out how that event came about".

"The bigger question is around this event being held in this venue, and that is something which is the biggest concern."

RILEY BAKER Emergency services and members of the public carry an injured person to an ambulance after the collapse in March 2016.

However cautioned against any "knee-jerk reaction" arising from the balcony collapse.





The building

The balcony was issued a building consent in 1999, with the report from DCL Consulting noting the joists supporting the balcony had fractured towards the root of the cantilever.

ANTHONY CHILCOTT-PARKER/SUPPLIED Eight people are seriously injured after a balcony collapsed during a Six60 concert on Dunedin's Castle St.

The balustrade was found in other intact balconies to be "excessively flexible", the report noted.

The report also noted there had been "vandalism" at another unit in the complex several years ago, and while that balcony did not collapse it did require repairs.

"Following this incident there was a cautious approach to the balcony loading during the event," the report noted after an interview with the property manager.

Tenants were warned to keep their flats locked during the event, and that "only the occupants of each unit should be allowed on the balconies".

That would restrict the numbers on the balconies to six, but further discussions with students pushed that limit to an "absolute maximum of eight".

That property manager Matt Cutler, of Cutlers, said prior to the collapse there were no warning signs limiting the amount of people on each balcony.

Signs saying the balconies were "out of bounds until further notice" were now in place, with each balconies to be altered and strengthened to "the highest standards" - five people per square metre.

The report found the balcony had an overload factor of 25%, based on the occupants at the time of the collapse each weighing an average 75kg.

That increased to 100% as " it is likely that the students were crowded into the right hand end of the balcony as the view to the band was in that direction".

The incident

A video of the incident showed there were 17 people on the balcony at the start of the Six60 gig, with two people moving as the music starts.

"The two individuals can be seen to move a couple of times. On approximately the third movement the balcony collapsed starting at the right hand end.

"The balcony did not collapse instantaneously, but collapsed progressively from the right hand end which dropped first. The sound of the fracture was not a single crack but was more of a very rapid ripping sound as each joist failed," the report noted.

The council's investigation included viewing 360-degree footage of the balcony collapse, which was filmed by Dunedin company Animation Research.

That 360degree footage, viewed by Stuff, was shot by Dunedin firm Animation Research and captures the shows the start of the Six60 concert.

The aftermath

Pickford said the concert wasn't a suitable location for the concert and as a city we need to work out the best way for students to have fun while they are in Dunedin, but to do it safely".

"We are all very aware students were seriously hurt as a result of this incident and we want to reduce the chances of anything like this happening again."

The two seriously injured students, Unahi and George Karamaena, who had since been discharged from Dunedin Hospital, were under the balcony when it collapsed.

Recommendations included assessing balcony materials to see if the remaining flat balconies needed strengthening.

The council had already suggested the property owners obtain independent engineering advice and strengthen balconies.

The report states a different loading standard for balconies, particularly in the student precinct, could be implemented if the Ministry of Business, Innovation and Employment (MBIE) changed the law.

The council would contact property management companies, and those who own high density residential buildings with balconies, to recommend reading the report and decide if further action is required.

A University of Otago spokeswoman said the tertiary institution supported the recommendations in the report.

"And will fully involve itself as a priority in discussions with the DCC, Police and others to come up with ways to ensure that safety considerations are more fully incorporated into the planning around future private events involving students in the North Dunedin area."

MBIE completed a separate report for Building and Housing Minister Nick Smith for his consideration, a spokesman said.