According to metropolitan government sources, the underground shelter would be a facility at which residents could take refuge if a protracted attack makes being aboveground dangerous. The facility would be equipped with food, water, ventilation equipment, emergency power sources, communication devices and other essential items that would enable people to stay for a long period. The metropolitan government plans to start drawing up a design that converts an emergency supplies warehouse within Azabu-juban Station into the new underground emergency shelter. Research costs for the project will be included in the initial draft budget for the next fiscal year. The shelter is expected to be completed in a few years. However, maintenance costs for such a shelter will run into hundreds of millions of yen, so constructing such facilities across the whole of Tokyo will be difficult. As a result, the metropolitan government hopes the private sector will take a larger role in providing such emergency facilities, such as by constructing buildings with underground spaces that could be converted into shelters.