In 20 years of rescue work spanning about 80 countries, Al Dwyer had never seen devastation as bad as in Christchurch in the hours after the February 22 quake.
Mr Dwyer, from the United States Agency for International Development, mobilised 72 fire and urban search and rescue staff from Los Angeles and chartered a jet to Christchurch.
Two days later, the team were on the ground and hard at work alongside local emergency services workers, battling aftershocks and debris in the frantic race to save lives.
Mr Dwyer had worked in quake-ravaged Haiti but said seeing Christchurch broken and battered was much closer to home.
"Christchurch, like the US, is a First World city and it's familiar. But when I got here, I'd never seen anything like it. It was like home," he told the Herald.
"Until then, New Zealand had always been a romantic destination that we'd all aspired to visit, never a place we thought we'd be coming to under these circumstances."
The USAID team were based in Latimer Square, a block from the devastated CTV building, alongside local rescue teams.
"This is what our fulltime jobs are. We work 24/7 when and where we're needed. We worked around the clock, and then the nature of our mission changed.
"Initially we were here for rescue. Then that rolled into recovery. We usually spend only 72 hours in a place, but because Christchurch was so major we ended up staying for 10 or 11 days."
Mr Dwyer said it was a privilege to be back at Latimer Square yesterday, where a moving ceremony was held in honour of those who did not survive the quake and of those who worked so bravely and relentlessly on the rescue and recovery effort.
"I came to bring closure. I came because my men wanted me to come back. We've got a real bond with the people here."
He said the thing he would remember the most about Christchurch was the community pride and spirit and the willingness to help.
Members of a local 4WD club turned up in their vehicles en masse to transport the USAID team and other international teams around the ravaged city. They were suffering their own losses and damage and still had to work, but every free hour they had, they gave up to help.
A launderette down the street took care of the USAID team's washing. Their building was destroyed, their washing machines thrown almost into the street, but they still put their hands up to help those helping their city.
Mr Dwyer remembers the food tent going from a coffee table with a few mugs and a box of doughnuts to - days later - a full "circus" tent of supplies all donated, and all appreciated.
"None of us had ever seen anything like this. Just to see that kind of support from the community ... These people were dealing with their own emergency but the support was amazing."