Police have announced they will not prosecute over the collapse of the CTV building during the 2011 Christchurch earthquakes.
The office block pancaked in the February 22 quake, killing 115 people.
A Royal Commission of Inquiry found flaws in the building's design and construction, but nobody has yet been held responsible.
Police started a criminal inquiry in September 2014. A legal review by Crown Law was completed, following an earlier review by the Christchurch Crown Solicitor.
Critical elements of the building's structure were physically re-built and tested as part of the investigation, along with specialist engineers examining the site and foundations.
James Coleman was joined by Susan Freeman-Greene Chief Executive from engineering New Zealand they discuss issues around engineering and flaws around accountability
Listen to the discussion above.