This graphic shows the pattern of the earthquake and aftershocks in Christchurch since Saturday morning:
http://www.christchurchquakemap.co.nz
The damage estimate has been doubled to NZ$4 billion today.
The aftershocks are causing further damage with cracks opening wider.
They have already started demolition of some of the 500 damaged buildings in the central city. Some will be saved and strengthened, but many will not.
Half the Building section from my work headed south today to help out with the assessments in Christchurch - they had to do the same job in Gisborne 2 1/2 years ago.
Rob