At 12.51 p.m. on Tuesday 22 February 2011, a magnitude 6.3 earthquake caused severe damage in Christchurch and Lyttelton, killing 185 people and injuring several thousand.
The earthquake’s epicentre was near Lyttelton, just 10 km southeast of Christchurch’s central business district. It occurred nearly six months after the 4 September 2010 earthquake.
The earthquake struck at lunchtime, when many people were on the city streets. More than 130 people lost their lives in the collapse of the Canterbury Television and Pyne Gould Corporation buildings. Falling bricks and masonry killed 11 people, and eight died in two city buses crushed by crumbling walls. Rock cliffs collapsed in the Sumner and Redcliffs area, and boulders tumbled down the Port Hills, with five people killed by falling rocks.
Although not as powerful as the magnitude 7.1 earthquake on 4 September 2010, this earthquake occurred on a shallow fault line that was close to the city, so the shaking was particularly destructive.
The earthquake brought down many buildings damaged the previous September, especially older brick and mortar buildings. Heritage buildings suffered heavy damage, including the Provincial Council Chambers, Lyttelton’s Timeball Station, the Anglican Christchurch Cathedral and the Catholic Cathedral of the Blessed Sacrament. More than half of the buildings in the central business district have since been demolished, including the city’s tallest building, the Hotel Grand Chancellor.
Liquefaction was much more extensive than in September 2010. Shaking turned water-saturated layers of sand and silt beneath the surface into sludge that squirted upwards through cracks. Thick layers of silt covered properties and streets, and water and sewage from broken pipes flooded streets. House foundations cracked and buckled, wrecking many homes. Irreparable damage led to the demolition of several thousand homes, and large tracts of suburban land were subsequently abandoned.
The government declared a national state of emergency the day after the quake. Authorities quickly cordoned off Christchurch’s central business district. The cordon remained in place in some areas until June 2013. Power companies restored electricity to 75 per cent of the city within three days, but re-establishing water supplies and sewerage systems took much longer.