Experts identified the fact that the CTV building's lift shaft, or core, remained standing after the rest of the building had collapsed as a key indicator of issues with the structural integrity. Professor Clifton said the fact that the lift core remained standing raised suspicions about the mechanism for holding the building together and handling the "lateral load" in a quake. The royal commission of inquiry would be looking closely at the issue, he said.
Experienced structural engineer Barry Davidson went further, telling the Weekend Herald in May: "Nobody needed to die."
The CTV building was designed by engineering firm Alan Reay Consultants, and built for a developer by Williams Construction - which has since gone into liquidation. In a statement to the Weekend Herald, Alan Reay Consultants said it wanted to help get to the bottom of what happened to the building.
"We have asked to be heard as part of the royal commission of inquiry ... until then it is premature to comment on what are complex issues. Like every other New Zealander, Alan Reay Consultants' management and staff were horrified by the collapse.
After a 7.1 magnitude quake struck in September, many of the occupants of the CTV building raised concerns about the movement of the building. Occupants reported noticeable shaking when heavy vehicles passed by.
Fears were heightened further by the powerful vibrations created as a building next to the CTV building was being dismantled - and holes were drilled in the back wall of CTV for wooden battens to be attached to support the demolition.
CTV cameraman Andrew 'Bish' Bishop, 33, told his mother Karen of his worries about how the building "creaked and groaned" in the weeks before he died in its collapse. His love for his job kept him turning up even though he felt uncomfortable being in the building, Mrs Bishop said.
"It was his passion, I guess, that cost him his life. Parents aren't supposed to bury their kids. It's the most horrific thing a parent can face."
Brian Kennedy, who lost his wife Faye in the building and co-chairs the Quake Families Group, said it was not a witch-hunt, but questions had to be asked. "You wouldn't expect a building of CTV's age to pancake the way it did when others considerably older - although they sustained damage - didn't react the same way CTV did," Mr Kennedy said.
If someone had "stuffed up", Mr Kennedy wanted to see them "front up to me and everyone else ... and say I'm sorry. It won't bring [those who died] back, but it's some closure. We can't sue. I don't think I would really want to."
CTV building owner Madras Equities said the building was deemed secure for occupation by the Christchurch City Council after the September 4 quake, and a detailed engineers' report raised no issues regarding the structural integrity.
Work was under way to repair superficial damage to the building fabric when it collapsed, the company said.
Madras Equities director Lionel Hunter said he lost a good friend in the building's collapse.
"If we had known anything was wrong with the building, I would have pushed it over myself."