 Complete the following phrase:  The tower was damaged during the 2010 Canterbury earthquake and the operation of the time ball stopped. The buildings were significantly damaged during the February 2011 Christchurch earthquake. The New Zealand Heritage Trust decided that it would be dismantled after engineering advice indicated that the building could not be saved due to public safety concerns, though they hoped to salvage the time ball mechanism and were investigating whether reconstruction was a viable option. The tower collapsed during an aftershock on 