The Japanese government has revised its basic plan for a capital-area earthquake to reduce the projected death toll by more than half [1].
This policy shift follows a 2025 revision of damage assumptions that painted a grim picture of the Tokyo metropolitan area's vulnerability. By setting concrete numerical targets, the government intends to move from general preparedness to measurable risk reduction in one of the world's most densely populated urban centers.
According to the revised plan, a magnitude-7 earthquake in the capital region could result in approximately 18,000 deaths [2]. The government now aims to reduce this projected figure to 9,000 or fewer within the next 10 years [1].
Fire prevention is a central pillar of the new strategy. Current data shows that seismic-breaker devices, which automatically cut power during tremors to prevent electrical fires, are installed in around 20% of buildings [1]. The government is now targeting the installation of these devices in almost all buildings to mitigate the risk of mass conflagrations [1].
Structural damage remains a primary concern for the Cabinet and relevant ministries. Worst-case scenarios project that about 400,000 buildings could be completely destroyed or burned [2]. This figure includes approximately 130,000 total collapses and roughly 270,000 buildings lost to fire [2].
Beyond infrastructure, the plan emphasizes individual responsibility. The government has set a new household emergency stockpile target, requesting that all households store at least three days’ worth of food and water [1].
To ensure these targets are met, the Disaster Management Agency will conduct annual progress reviews. The government said it may use its authority to issue recommendations if progress lags behind the established timeline [1].
“The government now aims to reduce this projected figure to 9,000 or fewer within the next 10 years.”
Japan's transition toward specific numerical targets and annual progress checks indicates a shift toward a more accountable disaster management model. By focusing on the 'seismic-breaker' installation rate, the government is acknowledging that preventing secondary disasters, such as urban fires, is as critical as the initial structural reinforcement of buildings to prevent mass casualties in the Tokyo area.
