The female urologist from Melbourne had to use what was at hand - a knife contained in a fold-out Leatherman multi-tool and a hacksaw - to amputate both legs above the knee.
She saved the 52-year-old's life. The man, who does not wish to be named, is recuperating in Waikato Hospital, and faces a long course of rehabilitation.
Brisbane urologist Dr Stuart Philip was nearby while his colleague from Melbourne performed the operation.
Dr Philip, who is originally from Hastings and spent eight years in Christchurch as a registrar, told the Herald last night that his colleague was so traumatised by the procedure she was unable to help any more earthquake victims and did not want to be identified or speak publicly about the experience.
They had been at a Christchurch urology conference which was cancelled because of the earthquake.
Some of the guests went to provide emergency care to earthquake victims, including those at the Pyne Gould building, 400m from the conference.
Dr Philip said he, his colleague and a Christchurch anaesthetist went to help a man whose legs were pinned under a large beam at the rear of the Pyne Gould building.
"The three of us made the decision that he had to have his legs amputated. The anaesthetist gave him some morphine and some ketamine - not a proper general anaesthetic but better than nothing. He was heavily sedated."
The female doctor was chosen to do the amputation.
"It came down to her because she was the smallest. It was a very tight space, down where his legs were. There was enough room to have the anaesthetist where his head was and one person in the space where his legs were.
"The two of them crawled into the building."
The operation took 10 to 15 minutes. They placed blood pressure cuffs around the man's thighs to control blood loss.
"It was a bilateral amputation performed with a Leatherman knife and a hacksaw. I don't know where we got [the knife] from. There was a whole lot of tradies [tradesmen] came to help us out and someone produced this Leatherman knife out of their pocket. The hacksaw was from a tradie that turned up."
After the amputation, the man was handed down to Dr Philip and a paramedic and put in an ambulance.
"He had a cardiac arrest just before we arrived at Christchurch Hospital. We performed CPR for a few minutes until he got some blood [flowing] and some good resuscitation."
After further surgery at Christchurch Hospital to tidy the wounds, the man was transferred to Waikato Hospital.
Here's a second article with more details.
Third article, in which another hero, a policeman was mentioned. Legs don't matter, he's alive.
The current death toll at Christchurch earthquake is