[Yashio City Road Collapse Accident] Nearly 1 Year and 8 Months Since the Incident: Drone Footage Shows “The Site Today”

The hole is still open.

“Ever since the sinkhole incident, the stench of sewage has been lingering, and because the road was closed, a lot of cars started using the alley near my house, which was a real hassle. Although things have improved somewhat now that the prefectural road has reopened, we’re still facing significant inconvenience because the city road remains cut off,”

So says a resident of Yashio City, Saitama Prefecture.

The road in the city suddenly caved in on January 28 of last year. A hole approximately 8 meters in diameter and 5 meters deep opened up near a six-way intersection.The cause is said to be hydrogen sulfide generated from sewage flowing through the sewer pipes, which corroded and damaged the pipes. The collapsed hole expanded to a diameter of 30 meters and a depth of 10 meters. At one point, 1.2 million residents in the surrounding area were asked to refrain from using domestic wastewater.

“Prefectural Route 54, which had been closed to traffic, partially reopened in April of this year after a bridge was built over the sinkhole (see the ‘Current’ photo above). Although it originally had four lanes, only two lanes have been restored so far, and according to the prefecture, traffic volume has recovered to about 80 percent of what it was before the sinkhole formed,” said a reporter from the social affairs department of a national newspaper.

That said, the remaining four city roads remain cut off, and a large hole still gapes at the site. The road to full recovery is long. An official from the Saitama Prefecture Sewerage Division explains why the construction is taking so long.

“The replacement of the damaged sewer pipes has already been completed. However, in addition to sewer pipes, infrastructure such as electrical, gas, and water lines are buried underground, so we need to restore them in order while filling in the holes. Since we are also proceeding with the expansion of the sewer system to dual lines, it will take up to seven years for the construction to be fully completed.”

Click here for Part 2 : [Yashio City Major Road Collapse Accident] Work Will Be Prolonged… Up to 7 Years Until Completion: “The Current Situation on Site”

From the October 2 & 9, 2026, combined issue of *FRIDAY*