The mayor of Christchurch has admitted the city council's handling of the September 2010 earthquake was not good enough.
A critical internal report says communication was poor, files were lost and the council did not appear to grasp the magnitude of what had happened.
It suggests the council prioritised reopening city bars and restaurants over safety.
The report is an assessment of the lessons learnt from the 7.1-magnitude quake early on 4 September that caused damage but no loss of life.
It was the first in a series of strong quakes to hit Canterbury - the most serious being a 6.3-magnitude tremor in February last year that killed 181 people and destroyed much of central Christchurch. Aftershocks continue to rattle the region.
The report says the council team evaluating dangerous buildings following the September quake showed poor communication and was overworked and under-resourced.
It also says most owners of property that was in danger were not notified of the fact.
The report also says the council did not declare a State of Emergency after the Boxing Day aftershock - despite requests from emergency services.
The report says the aftershock on 26 December resulted in significant damage to 161 buildings.
But it says within six hours, the focus of the response appeared to have moved from accurately establishing the public safety risks to opening the city and ensuring that New Year's Eve celebrations went ahead.
The report also says had there been loss of life or injury, it's unclear whether the council could have shown it had followed due process.
Mayor Bob Parker told Radio New Zealand's Summer Report programme on Monday he admits there were failings.
"No, it's not good enough. But the purpose of the report was to determine exactly where the issues were. It was very critical also, I think, of some of the decisions that were taken after the Boxing Day earthquake (in 2010).
"(The report) felt that there was too much emphasis put on the commercial activities and getting those open as quickly as possible."
However, Mr Parker is confident the council has now addressed the problems.
"Many of our files were trapped in buildings that were unserviceable that we couldn't get into. So there are a number of mitigating circumstances but, overall, I think the organisation's handled these extraordinary events very well indeed."
Mr Parker says the document does not cover the many positive aspects of the council's response.