Christchurch sits near the diagonally opposite side of the Pacific subduction zone that could cause the big one to happen off the coast of Oregon. This area had back-to-back big earthquakes September 2010 and again in February 2011. We spent 2 of our 3 full days in Christchurch taking their Rebuild Tour, going to the quake museum and just walking around seeing the damage.
Now, almost six years on, much of the inner city is still empty lots or fenced off lots waiting to be demolished or repaired. 70% of the central city was either destroyed or had to be demolished because the buildings were beyond repair.