has built a radiated and circular grid between power plants and urban/industrial demand areas. Each transmission line is designed to transmit electricity at high-voltage (66-500kV) between power plants and substations. Normally transmission lines are strung between towers, but within the Tokyo metropolitan area high-voltage lines are located underground. From substations, electricity is transmitted via the distribution grid at low-voltage (22-66kV). For high-voltage supply to large buildings and factories, distribution lines are directly connected to customers' electricity systems. In this case, customers must purchase and set up transformers and other equipment to run electric appliances. For low voltage supply to houses and small shops, distribution lines are first connected to the company's transformers (seen on utility poles and utility boxes), converted to 100/200V, and finally connected to end users. Under normal conditions, TEPCO's transmission and distribution infrastructure is notable as one of the most reliable electricity networks in the world. Blackout frequency and average recovery time compares favorably with other electric companies in Japan as well as within other developed countries. The company instituted its first-ever rolling blackouts following the shutdown of the Fukushima I and II plants which were close to the epicenter of the March 2011 earthquake. For example, on the morning of Tuesday, March 15, 2011, 700,000 households had no power for three hours. The company had to deal with a 10 million kW gap between demand and production on March 14, 2011. Accidents and controversies Safety incidents On August 29, 2002, the government of Japan revealed that TEPCO was guilty of false reporting in routine governmental inspection of its nuclear plants and systematic concealment of plant safety incidents. All seventeen of its boiling-water reactors were shut down for inspection as a result. TEPCO's chairman Hiroshi Araki, President Nobuya Minami, Vice-President Toshiaki Enomoto, as well as the advisers Shō Nasu and Gaishi Hiraiwa stepped-down by September 30, 2002. The utility "eventually admitted to two hundred occasions over more than two decades between 1977 and 2002, involving the submission of false technical data to authorities". Upon taking over leadership responsibilities, TEPCO's new president issued a public commitment that the company would take all the countermeasures necessary to prevent fraud and restore the nation's confidence. By the end of 2005, generation at suspended plants had been restarted, with government approval. In 2007, however, the company announced to the public that an internal investigation had revealed a large number of unreported