At least 14 people remained trapped in the mangled Pyne Gould Corporation building facing a second cold and lonely night while rescue teams continued to work around the clock.

Yesterday, four survivors were pulled from the rubble, including Ann Bodkin, who had been trapped in a cramped spot for more than 25 hours.

Her husband, Graham Richardson, was waiting for her as she was tied to the end of a fire truck's ladder and lowered to the ground.

"Getting her out is just stupendous. I'm a very happy man," an emotional Mr Richardson said.

When she was brought out into the light, he said, she couldn't even turn to look at him because of her neck brace. She could only giggle her elation.

Mr Richardson said he could not describe the feeling when he was first told that she was still alive inside the building. "I was told to get myself down here because she was asking for me. I didn't break any speed limits but I got here pretty quickly."

Ms Bodkin's father, Bill Bodkin, and his wife, Shirley, were at home in Clyde when the earthquake struck.

"We lost a son a few years ago in a mining accident in Australia," Mr Bodkin said. "We feared the worst and thought we'd lost another one. We got a call from Graham to say he had heard from the police and they'd found Ann alive, but trapped in a difficult position. She was very cold and wet from the rain but she was alive."

"Ann is one of the miracles of the day," said Christchurch Mayor Bob Parker. "When you feel something like that it's a moment of hope and optimism."

PGC chief executive Jeff Greenslade said there were still 14 people in the building unaccounted for, while 10 people had been rescued so far.

He did not know of any fatalities, and was trying to remain optimistic that the others would still make it out.

But PGC and its subsidiaries, Marac and Perpetual Trust, occupied only half the building, and there were almost certainly more workers in the building at the time of the earthquake.

Mr Greenslade praised volunteer rescuers Jason Sutherland and Carl Stockton, who worked 12 hours straight, cutting through a jungle of concrete and debris to get to people crying out for help.

"Some people we had to crawl over and leave there to get their friend out because they had passed away," Mr Sutherland said.

It took five or six hours for them to cut their way through to levels two and three.

"It's just a tangle of debris and rubbish. You had to saw things, you had to cut things, pull things out of the way. It was very difficult. And there were aftershocks all the time."

In that initial sweep, seven people were rescued, most of them uninjured.

"They were really calm, like nothing happened. No scratches. Nothing. Just confined and stuck because they got under the tables or did whatever they did to save themselves," Mr Sutherland said.

"They were just happy to be out, happy to breathe and happy to see daylight."

Saving people's lives was "better than winning lotto".

Mr Greenslade said he was totally shocked by the damage to the building, which PGC sold a couple of years ago to a private investor. It had been properly tested after the September 4 shake, when the only damage was a couple of filing cabinets falling over.