EVIDENCE is one thing, the human heart is something else.
Despite the grim reminders all around of death and destruction, rescuers clung on to the slenderest of hopes that survivors might still be found.
Tired and drained by their relentless efforts, the teams insisted that they were "optimistic" that more people would be pulled alive from the rubble following the devastating earthquake which hit Christchurch, the leader of a British disaster relief team said last night.
Firefighter Scott Imray told how emergency workers are working gruelling 12-hour shifts in a bid to find quake survivors.
Mr Imray is the leader of an international search and rescue team from Grampian Fire and Rescue Service, which flew out to New Zealand's South Island earlier this week.
He described the scene of devastation which met the rescue team when they arrived on site.
He said: "It's very saddening looking at the destruction.
"The buildings are similar to back home but there's destruction all around in the centre of Christchurch itself.
"We're in search and rescue mode and we will be doing our utmost to bring out live casualties.
"We are very optimistic that we could still come across live casualties."
Mr Imray said more than 500 rescue workers would soon be working on the site.
"When all the teams . . . have arrived, there will be a total of 400 international search and rescue personnel and we will be supporting 130 urban search and rescue personnel from the New Zealand task force who have been here from the start," he said.
He told how the rescue teams face a number of challenges as they go about their work, including the constant threat of aftershocks. But he insisted that morale among his team remained "excellent".
"The challenges are obviously the dangers that are still around due to the unsecured structures we will be working on and the problems posed by the dust, dirt and debris," he said.
"There are continual aftershocks throughout the day and night.
"The morale in the Grampian team is excellent.
"And the people on the ground, the nationals here, are upbeat and they are very supportive. Even the pilot coming down from Auckland to Christchurch announced us on the plane and we got a round of applause from the other passengers on board.
"A lot of the personnel in the New Zealand fire service there have been affected and their homes have been affected, but they're still working here, they're still upbeat and carrying on and doing their utmost," Mr Imray added.