2011 Tōhoku earthquake and tsunami additional power, because TEP's power plants were also damaged in the earthquake. Kansai Electric Power Company (Kepco) cannot share electricity, because its system operates at 60 hertz, whereas TEPCO and TEP operate their systems at 50 hertz; this is due to early industrial and infrastructure development in the 1880s that left Japan without a unified national power grid. Two substations, one in Shizuoka Prefecture and one in Nagano Prefecture, were able to convert between frequencies and transfer electricity from Kansai to Kanto and Tōhoku, but their capacity to do so is limited to 1 GW. With the damage to so
2011 Christchurch earthquake in May 2012. The 21-storey PricewaterhouseCoopers building, the city's tallest office tower, is among the office buildings to be demolished. The Carlton Hotel, a listed heritage building, was undergoing repairs after the September 2010 earthquake damage when the February 2011 earthquake damaged the building further. It was deemed unstable and demolished in April 2011. St Elmo Courts has been damaged in the September 2010 earthquake and the owner intended to repair the building, but further damage caused by the February 2011 event resulted in a decision to demolish, which was done the following month. The historic Canterbury Provincial Council Buildings