This aerial view of Christchurch's central business district in early 2013 shows the extent of the demolition undertaken following the 2011 earthquake – and more buildings were demolished subsequently. Most of the demolished buildings were older structures that were deemed too unsafe by the Canterbury Earthquake Recovery Authority (CERA) to retain. This assumption was vigorously disputed by heritage advocates, who argued many buildings could have been easily strengthened if there had been the will to do so.