Christchurch's devastating 6.3 earthquake is thought to have been caused by the rupturing of a single fault.

Adrian Marsh thought he was dead after he was crushed by slabs of concrete when the Smiths City carpark collapsed around him.

Christchurch can be rebuilt in a way that buildings would withstand very strong earthquakes in the future, Prime Minister John Key says.

Thousands of Christchurch's 350,000 inhabitants have left in droves, flying, driving, even walking away, with no plans to return any time soon.

Emotion is fine but cool heads are needed for Christchurch's rebuilding, writes Chris Rattue.

Trapped in excruciating pain for hours while pinned under a concrete wall, Brian Coker wanted a "decent aftershock to finish it". Instead, the 52-year-old says his wife saved by alerting rescue teams to his plight.

New Zealand could make much greater use of satellite images, says Southland group.

As Rob Cope-Williams looks at search and rescue workers picking through the crumbled mess of the CTV building, tears silently roll down his face.

Jayden Andrews-Howland, 14, was on a bus into town and has not been seen or heard of since last Tuesday's earthquake in Christchurch.

166 disaster victim identification (DVI) staff are working in shifts to formally identify victims of the 6.3-magnitude quake.

The co-owners of the health clinic flattened in the collapse of the CTV building were receiving counselling yesterday and expressed their sympathy for the families of missing staff.

Some Christchurch renters fleeing the shaken city are getting little charity from landlords, who are trying to keep them locked into contracts.

Commitment shown by business leaders to help Christchurch recover is a show of solidarity but also the right call economically, says BusinessNZ chief executive Phil O'Reilly.