A Christchurch emergency medicine specialist says a well-developed and practised city-wide plan helped save lives in the earthquake in February last year.
Professor Mike Ardagh makes the comment in an article published today in British medical journal The Lancet.
He says Christchurch was unique in having one acute hospital serving an area with about 450,000 people.
There are seven hospitals in the city in all, and several non-acute ones responded, as did family doctors, in accordance with well-developed and practised internal and external incident plans.
Professor Ardagh says 6659 people were injured in the first 24 hours following the earthquake and 182 died.
Severe shaking in the main hospital meant staff were unable to stand unaided, and power was lost.
Other difficulties included little information about what was happening outside, and tracking of patients.