Canterbury Earthquake Recovery Minister Gerry Brownlee says a 40 tonne boulder that crashed through a Port Hills home on Wednesday night is proof there is still real risk around Canterbury.
Mr Brownlee said the rock roll is a graphic illustration of the ongoing unpredictability of the damaged land.
The area was zoned red after computer modelling showed the risk of rock roll is still high.
Owners of some of the properties in the zone have appealed against the ruling, which the Canterbury Earthquake Recovery Authority is now reviewing.
