Cantabrian Kiri Reynolds decided to leave Christchurch after seeing her 6-year-old son vomit and cower under a table during a series of aftershocks.
Kiri, who left with two of her three children for Kaikoura this year, is among the thousands of people to leave Christchurch since the September 2010 earthquake.
A total of 16,600 people quit Christchurch in the two years to June 2012, according to new figures from Statistics New Zealand.
The population exodus has slowed down, but 6000 people still left the city in the year to June.
Parents with children were most likely to leave the city, while people over 50 were more likely to stay, figures show.
The fall in population was also affected by 2900 fewer people aged between 15 and 19 moving to the city to study over the two years.
However, young male workers are moving to the city, with the male population aged 20 to 34 rising by 500 over the two years.
The departure of 6000 people from Christchurch in the year to June was offset by a natural increase of 1400 people over the same period.
This means Christchurch's net population fell by 4600 people, or 1.2 per cent, compared to a net loss of 8900 people, or 2.4 per cent, for the year to June 2011.
Kiri said her son Kiarn, 6, developed asthma because of the dust after the earthquakes, and the rest of the family started suffering from respiratory problems.
"After the December one seeing my son vomiting and white and under the table absolutely petrified I thought, ‘Oh my God what are we doing?'."
They had an opportunity to move to Kaikoura, buy into a transport business and rent out their house, so they took it.
However the Reynolds' oldest child, Savannah, 15, stayed in Christchurch because she was in her final few years of school. "It's very hard having the family split. . . it tore me apart."
But now, the family hope to return to Christchurch.
"It's my home, it's my town, it's where I grew up. I have lived around the world and you can't beat Christchurch."
The Canterbury earthquakes reversed a long-standing trend for steady population growth in Christchurch.
The earthquakes have also slowed population growth in the South Island as a whole. The South Island population grew by just 200 people in the two years to June.
- © Fairfax NZ News