Seven Months After the Yashio City Road Collapse: Aerial Look at the Devastation and the Long Road to Full Recovery

Complaints from Nearby Residents

Walking downwind of the accident site, a foul smell reminiscent of a ditch hits the nose. Seven months have passed since the road collapse accident in Yashio City, Saitama Prefecture, which occurred in January this year. A woman in her 20s living nearby speaks:

“There’s the smell of fuel from construction vehicles and the stench of sewage lingering all around. The noise from the construction is also terrible. Perhaps due to hydrogen sulfide leaking from the sewage pipes, the chrome on my private car has corroded and darkened.”

On January 28, a large-scale collapse occurred on a prefectural road in Yashio City, spanning 40 meters in width and 15 meters in depth. A passing truck fell into the sinkhole, resulting in the tragic death of the 74-year-old driver. We aerially surveyed the current state of the accident site.

“The prefecture is still investigating the cause of the collapse. It is believed that a sewage pipe over 4 meters in diameter corroded and broke, allowing a large amount of soil to flow into the pipe, creating an underground cavity that caused the road to collapse,” said a reporter from a national newspaper’s social affairs department.

At the site, surrounding roads are closed off, and many construction vehicles have been deployed as restoration work continues. However, complaints about the foul odor and noise from nearby residents keep pouring in. The prefecture’s consultation office has received about 90 complaints just about the smell. The prefecture distributed deodorizing machines to residents, but there’s no end in sight for the crucial construction work.

“The installation of temporary drainage pipes is complete, and we are currently removing the collapsed concrete debris and soil. We aim to lay new sewage pipes by the end of the year, followed by a plan to double the sewage pipes nearby. Full restoration will take between five to seven years. The budget is estimated to be about 30 billion yen,” said a representative from the Saitama Prefecture Sewerage Bureau, Sewerage Project Division.

Road collapses are not just a problem in Yashio City. Aging sewage pipes are a nationwide issue. According to the Ministry of Land, Infrastructure, Transport and Tourism, out of approximately 500,000 km of sewage pipes in Japan, about 40,000 km have exceeded the standard 50-year lifespan. Furthermore, 40% of all pipes will reach their lifespan by 2043, 18 years from now. On August 25, the ministry announced that underground cavities were found at 4,739 locations along national highways, with 119 spots posing a risk of collapse. There could be a sudden increase in major accidents like the one in Yashio City.

Professor Masahiro Yoneda, an expert on aging infrastructure and emeritus professor at Kinki University, points out:

“Repairing and renewing aging sewage pipes is an urgent issue. However, there is a severe shortage of civil engineers responsible for this work in both public and private sectors. It is urgent that the government takes the lead in establishing a system to secure necessary funding and nurture and secure engineers. Delays will cause sewage system dysfunctions, posing serious public health risks across Japan.”

The risk of road collapse and widespread foul odors seen in Yashio City is lurking nationwide.

From the September 12 and 19, 2025 issue of “FRIDAY”