At 12:15pm on the 22nd February 2011 a 6.2 magnitude earthquake shook Christchurch and surrounding areas. The epicentre was situated 6.7 kms SE of the city centre and was only 5 kms deep.

Although this shock was smaller than the 7.1 Canterbury earthquake of September 2010, its effect was far more devastating. Many buildings had been weakend by the Canterbury quake and subsequent, significant aftershocks. Many of the weaknessess were not known as they were inaccessible to engineers. Also this February 2011 quake had both lateral and vertical shaking causing some already earthquake strengthened and other brick buildings to suffer extensive damage.

By 2015 a total of 1240 buildings in the central city had been demolished. Among these were 43% of Christchurch's heritage listed buildings which owners could not afford to repair or rebuild.

The collapses of the six storey CTV (old Christchurch Television) building and the four storey Pyne Gould Guiness House caused 115 and 18 deaths respectively. Two people were killed by rockfalls on the Port Hills and 50 by falling masonry either crushing them directly or the vehicles they were in. This adds to a total of 185 deaths.

In the northeast of Christchurch an estimated 200,000 tons of liquefaction, soil turned into a liquid by shaking, caused major damage to roading, infrastructure and the land. A 648 ha (1,600 ac) residential red zone, in which 10,000 people used to live, has been formed on both sides of the Avon River.

More Info: en.m.wikipedia.org