A seismic engineer says many of the Christchurch buildings destroyed in Tuesday's quake weren't designed to cope with such intense forces - and it's possible damage from the September 4th earthquake went undetected.
Some parts of central Christchurch may have been hit by rogue seismic energy during last week's earthquake, amplifying the level of destruction.
A year after the first earthquake on 4 September 2010, aftershocks continue to be felt in Canterbury, and they're not always seismic ones. When buildings collapse or are cordoned off, or even just closed for repairs - what happens to the lives and livelihoods of those who used to fill them with noise and energy? Kris Vavasour returns to Lyttelton to catch up with performers and friends, to hear about life in an altered landscape.