• 'Sad Day' as shops demolished
"I'm tired, but you just keep going.
"When you're busy you keep going."
As the officer in charge of the police response from the emergency operations centre, Sgt Burke arrived at the Christchurch Central Police Station 30 minutes after the quake and worked for the next 15.5 hours. He was back at 7am the next day and worked a 12-and-a-half-hour shift.
He did the same again yesterday.
Sleep, what he was able to get between aftershocks, was had at his girlfriend's parent's house because his girlfriend was too scared to stay at their home alone, he said.
He coped by keeping busy.
"I have seven different things going on in my mind all the time.
"I think it's best being busy actually; you only really get tired if you stop to think about it."
And Sgt Burke is only one of a group of senior emergency services, council and contracting staff who have been working practically non-stop since 4.35am on Saturday.
Another one in for the long haul is Di Keenan, who has only had about an hour's sleep since the earthquake.
As communications manager for the Christchurch City Council, for the past three days, she has been attached to front man Mayor Bob Parker, dealing with the media almost non-stop and running a core team of communications people.
"We're keeping a pretty hectic schedule."
The media's assistance with quake information was vital at this stage, she said.
The council also knew interest would wear off in another few days, so it was vital to assist with all requests as long as possible.
Because of the international interest, calls were coming in all day and all night.
"It is a hectic schedule, and we expect it to carry on like this for the next few days.
"It's the adrenaline that keeps you going."
Senior firefighter Brian Reid and Station Officer Peter McArdle, from the St Albans Fire Station, said they had been on the go for more hours than they cared to count.
"There's a lot of us [firefighters] who have been on [duty] for 24 hours.
"There's some who've been going for 72 hours," Mr McArdle said.
Having firefighters come in from Dunedin, Invercargill and Auckland and the odd half-hour back at the station for a cup of tea or a lie-down was a life-saver.
Cellphones also made it much easier to cope these days.
"You get texts keeping you updated on what's happening at home and with the family, but other than that, you just keep busy," Mr Reid said.
"You go through the motions you know.
"I think you just do it.
"There'll be time to think about it later, when it's all over."
THE STATS:
• 100,000 houses damaged
• 100 aftershocks
• 250 in welfare centres
• 1000 homes without power