As the fourth anniversary of the earthquake which devastated Christchurch approaches, the slow pace of the rebuild has surprised many. But how quickly have other earthquake hit cities returned to their former glory? Radio New Zealand Christchurch reporter, Rachel Graham, visited Japan for an Insight documentary to compare the progress made in the Sendai area, almost four years after it was hit by a magnitude 9 earthquake and a mega tsunami. She also visited Kobe to look at the impact on that city, and the lessons learnt, 20 years after it was hit by a major earthquake.