This month marks the 100th anniversary of the 1923 Great Kanto earthquake that struck the greater Tokyo area. That disaster saw approximately 105,000 lives lost, of which around 91,000, or 87%, were due to firestorms that quickly spread through neighborhoods filled with densely crowded wooden homes.

Post-earthquake and post-war, the city has become less of a fire risk due to road widening projects and newer construction built from non-flammable materials. However, there are still 8,600 hectares of these risky crowded neighborhoods with old wooden buildings. These neighborhoods are the target of the local government’s ambitious plan to create a safer city in the event of a major disaster.

Many of these neighborhoods can be found around the outside of the JR Yamanote Line, particularly in Arakawa and Taito wards. Just after the 1923 quake, wooden rowhouses or ‘barracks’ were quickly built to house workers that were brought in to rebuild the city. These tenements are where most of the crowded wooden neighborhoods originated from. The city did embark on some major land readjustment projects shortly after WWII but a shortage of public funds limited these projects to important station areas on the Yamanote Line. Districts that survived the earthquake and WWII air raids have retained their original narrow laneways and crowded atmosphere to this day.

And while these old city blocks may be charming in their own way, they represent a serious risk to residents in the event of a disaster like an earthquake. The city began designating certain high risk areas in 2013, providing assistance to encourage rebuilding and redevelopment in the form of subsidies and reduced property taxes. There has been noticeable progress, with the number of densely packed neighborhoods dropping to 8,600 hectares by 2020, down from 24,000 hectares in 1996, however the rate has been slow.

Some of the challenges slowing down the progress have been due to complicated land ownership issues that have held up road widening plans. It is also a painstakingly slow process to negotiate with property owners and tenants.

The most recent earthquake disaster simulation announced in 2022 predicted a maximum of 6,200 deaths and 194,400 buildings destroyed by fire or collapse. This is a 30% decrease from a 2012 simulation. That same year, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) identified 1,875 hectares of densely-crowded districts in 12 cities and prefectures that carry high risk of fire spreading and evacuation difficulties for residents. While the definition varies from that of Tokyo Government’s, the district with the largest share of at-risk neighborhoods was actually Osaka with 895 hectares, followed by Kanagawa with 301 hectares, and Kyoto with 220 hectares. Tokyo was in 6th spot with 83 hectares. This is primarily due to efforts to eliminate these dense neighborhoods, which has been spurred on by the development of high-rise apartments.

Jiji Press, August 19, 2023.
The Asahi Shimbun, August 30, 2023.