2010 Canterbury earthquake

The 2010 Canterbury earthquake was a powerful 7.1 magnitude earthquake, which struck the South Island of New Zealand at 4:35 am September 4, 2010 local time (16:35 3 September UTC). 
It was centred 40 km west of Christchurch, near the town of Darfield, at a depth of 10 km. Strong aftershocks were reported, including ones of magnitude 5.3. 
The main quake was felt widely across the South Island, and in the North Island as far north as New Plymouth.
It caused a lot of damage and cut off power and water supply, mainly in the city of Christchurch. Two people were seriously injured. The quake caused damage to historic buildings in Lyttelton, near Christchurch, including a church and parts of a hotel. Businesses in the city centre were closed the day of the quake. The total cost of damages may be as high as NZ$2 billion.
A state of emergency was declared by Civil Defence for Christchurch and the Selwyn District.
Geological background.
New Zealand sits on the boundary between the Australian and Pacific plates. In the South Island, these plates mainly slide past each other horizontally, producing earthquakes along fault lines such as the Alpine fault. The 2010 earthquake was centred about 80–90 km to the southeast of the plate boundary through the island, probably on one of a network of smaller faults linked to the main faults that mark the plate boundary itself.