"I don't think you really appreciate it until you actually see it. It's just mind-blowing," firefighter Jason Hill said.
He and three other Dunedin firefighters, Simon Smith, Chris Kennett and Sean Yates, arrived in Christchurch on Monday and expected to be there until at least tomorrow.
Since they started work, they had more or less pulled down chimney after chimney non-stop, grabbing food and coffee when they could.
In an hour yesterday they had eight jobs: six chimneys and two false alarm calls.
"It's pretty busy all right. I'd never even pulled a chimney down before this and now we are doing one every 10 minutes," Mr Hill said.
The main damage was not what they had expected to see, he said.
"We'd seen the CBD on the television, and that was really bad, but the damage is really, really bad out in the suburbs. You move out into the residential areas and see the damage to the infrastructure, the roads, the water.
"The houses have big cracks in them, the walls are falling off, the chimneys are down. It's really devastating."
Also surprised by the damage was Dunedin City Council building control officer Ray Bremer.
He is one of four council building inspectors who started work in Christchurch yesterday assessing the immediate safety of buildings.
Four more are being sent and more are expected to follow later.
Mr Bremer, Chris Randall and Ricky Berland spent the afternoon inspecting homes as part of 12 teams working in Brooklands, one of the worst affected suburbs of Christchurch.
The council's chief building control officer, Neil McLeod, was based at the emergency operations centre at the Art Gallery in Christchurch, where he was working until 11pm yesterday.
"Basically, Dunedin is offering any assistance it can to help Christchurch out."
St John southern region operations manager Doug Third is also in Christchurch assisting with St John operations over the disaster relief effort.
