Hundreds of Christchurch residents are spending the night in the city's parks as rescuers continue to scrabble through the ruins of collapsed buildings in search of survivors from Tuesday's massive earthquake.
Prime minister John Key is warning the death toll of 65 is likely to rise after the 6.3-magnitude quake struck New Zealand's second largest city about 12:50pm local time.
Helicopters and cranes have already plucked terrified survivors from danger, but more than 100 are still missing after scores of buildings were reduced to rubble within seconds.
The spire of the city's historic cathedral also crashed to the ground in the second major quake to hit Christchurch in five months.
Cold temperatures and rain is making it harder for the people gathered at evacuation centres.
Around 1,500 people are camping out in wet conditions in a city park as welfare centres fill to overflowing. Many have only a board to sleep on or a tarpaulin for warmth.
- At least 65 confirmed dead
- Second major quake to hit city in five months
- Extensive damage in city, power cuts
- City has run out of ambulances
- 5.6-magnitude aftershocks recorded
- Australia sends search and rescue teams
- Contact DFAT on 1300 555 135
Mr Key says his nation is witnessing its "darkest day" and described Christchurch as a scene of utter devastation.
"It's just so vastly different from the last earthquake where there was some horrifying scenes, but this is a central city at a very, very busy time where you've had a massive earthquake," he said.
"It's been violent shaking on what was probably already weakened infrastructure. So you've in a way had the very worst of situations.
"People are just sitting on the side of the road, their heads in their hands. This is a community that is absolutely in agony."
Emergency workers say the degree of damage to city buildings is immense, made worse by at least 12 aftershocks, some of which measured up to 5.9 in magnitude.
Rescue teams will work through the night, roaming the streets using sniffer dogs to locate survivors and bodies.
Local television is carrying images of people being lifted out of buildings and distressed residents trying to locate loved ones and friends.
The Federal Government is trying to confirm the safety of Australians in the region.
Around 750 are known to be in Christchurch but up to 8,000 could be in the wider Canterbury region, but there are no reports so far of Australians unaccounted for.
Australian search and rescue personnel and medical teams are being sent to the city.
Christchurch mayor Bob Parker says the situation is about as bad as it could get.
"We've got people across the city who are trapped in buildings," he said.
"I don't think we are talking about thousands, but we are certainly talking about dozens of people who may not be able to be saved.
"[But] we are treating every one of these operations as an operation searching for people who we will save."
Mr Parker says water supply has been severely disrupted and residents should not shower, bathe or flush their toilets.
"Dig a hole in the backyard if that's actually what it takes," he said. "Save your water for drinking."
Alistair Dumbleton lives in the suburb of Lyttelton, which is near the epicentre of the quake.
Radio and television reported damage in the town as severe, with a landslide crushing a small building while passersby fled for their lives from underneath a collapsing awning.
"There's houses which were bricks and all the bricks have been removed, so you can see wooden framework," Mr Dumbleton said.
"There are roofs which have been shaken to pieces, so all the tiles off the roofs have completely gone. There's a train that's been derailed down in the valley. There's cracks in driveways, roads."
He was in the city centre at the time of the strongest tremor.
"I stood at the Cathedral tower; the very famous tower in Christchurch fell apart right in front of me," he said.
"I couldn't believe it was happening and I'm sure there were people there that were crushed under the bricks.
"It's taken us two-and-a-half hours to get back to our home on the outskirts of Christchurch where the epicentre was, and I haven't heard of any injuries here. All my friends and family seem to be OK."
Services stretched
Christchurch Hospital is in operation but the city's ambulance service was so stretched that police wagons were used to ferry injured people. More ambulances are on the way.
The chief executive of Canterbury District Health, David Mates, says hospitals are finding it hard to cope with the number of people coming for treatment.
"A number of spinal injuries and obviously broken bones and lacerations. We're also seeing a lot of chest pains and heart attacks presenting as well," he said.
Christchurch doctor Alistair Blomley has been treating the walking wounded at his surgery, about five kilometres from the city centre.
He says patients have described the devastation in some of the hardest-hit areas.
"Certainly the people who've come from the centre of town describe it like a scene from MASH, or a bomb zone," he said.
"They're just horrified by the speed at which life goes from relatively normal to absolutely horrific."
The government has declared a level 3 emergency and called on anyone still in the city centre to get out as the aftershocks continue.
Many people are unaccounted for, including workers at the flattened Pyne Gould building.
Scores of people were in the four-storey office block at the time.
One tenant, financial services company Pyne Gould Corporation, had about 60 workers in the building.
The company's chief executive Jeff Greenslade told ABC Radio's PM that more than half of those workers are accounted for.
Unaccounted for
"We swung in to action in terms of our disaster recovery and we were able to start making contact with staff just to ascertain where they were," he said.
"We need to just go through the process of just ascertaining whether some staff were on leave, some had gone off for lunch.
"It hit around about lunch time so that was fortunate and then the process of making contact with those who had been in the building and managed to get out."
He says staff are devastated but hoping for the best.
"Everybody's kind of glued to the TV and watching people being hoisted off the building and taken out, so we just remain hopeful."
Despite the devastation there have been some remarkable stories of survival.
Jeff McLay managed to escape the Pyne Gould building despite his office ceiling and floor collapsing.
"I started to run towards the middle and then the floor just went from underneath us," he said.
"The concrete beam, which is about 3 metres full, must have compressed to about 1.5 metres and we were trapped in there between the two floors; thrown to the ground. We were all thrown to the ground."
Australian help
Attorney-General Robert McClelland says an Australian search and rescue team will arrive in New Zealand overnight and more will be sent this morning.
"It will have expert search, rescue, medical engineering and support capabilities, including search dogs attached to that team," he said.
"It will be available and ready to undertake duties at first light tomorrow morning in New Zealand."
Foreign Affairs Minister Kevin Rudd says the unfolding scale of the disaster is heartbreaking.
"When you have so many large buildings which have collapsed like wedding cakes into rubble, and it's the middle of a working day, we have grave fears," he said.
"Hence, the Attorney's predisposition, certainly the Prime Minister's predisposition and my predisposition was to throw everything forward as rapidly as possible."
