A painstaking recovery operation at the CTV building which collapsed in the Christchurch earthquake is expected to be finished in about three days, the Fire Service says.
Many pepole were killed after buildings in the central city collapsed on 22 February, including the CTV and Pyne Gould buildings and Christchurch Cathedral.
The death toll from the 6.3-magnitude quake stands at 163 on Friday, but officials fear it could go as high as 220.
More than 100 people may have died at the CTV building which housed staff from Canterbury Television and an English language school.
The Fire Service's Assistant Commissioner, Paul Baxter, says Chinese, Japanese and New Zealand teams have been working on the building in daylight hours.
Teams are working around the clock at the Forsyth Barr building, but are having to work their way down due to a collapsed stairwell.
The leader of an American search team clearing the site says staff have been removing the wall on one side of the stairwell on Friday to reach concrete debris that needs to be broken up and removed.
Battalion Commander John Lenihan says the focus is on recovering the bodies of anyone still inside, but high winds have sometimes prevented the use of a crane to gain access above the fifth floor.
However, he says the team has so far cleared about half a floor worth of concrete from the stairwell tube where debris from about five floors has fallen.
Meanwhile, Mr Baxter says teams are continuing to work day and night at Christchurch Cathedral where it is believed about 20 people were crushed by falling debris.
"We have started a controlled clearance of the spire, starting with the clearance of the upper layer of a huge amount of debris in that building. For safety reasons, the Urban Search and Rescue personnel are working from a specially constructed steel capsule lowered into the base of the spire by a crane.
"The recovery operation is a very difficult one and we're protecting as much of the building as we possibly can while doing the job we have to do."
Mr Baxter says the remainder of the central business district has been prioritised by engineers and there are currently 30 buildings on that list.
Many heritage buildings unsafe
By Friday afternoon, 56,000 properties had been inspected. This includes 3000 properties within the four avenues - 45% of which have been given red or yellow stickers to restrict access.
Of the 1000 heritage buildings inspected, exactly half of the Category 1 and 2 listed buildings have been given red stickers, meaning they are not safe.
Some 1350 homes in the wider city have also been deemed unsafe.
Work at Pyne Gould finished
The recovery operation has been completed at the collapsed Pyne Gould building.
Civil Defence national controller John Hamilton says British rescuers working on the Pyne Gould site have been deployed elsewhere on Friday.
Ann Bodkin, the last person to have been rescued from a building following the quake, feels there must have been something wrong with the Pyne Gould building because it colllapsed so quickly.
"It was so sudden - for me it was bang, bang, bang and then silence. It was so fast. That building collapsed in no time at all."
An investigation will look at the clearance given to the Pyne Gould and Canterbury Television buildings.