Four workers in Gyoda City, Saitama Prefecture, north of Tokyo, died in a serious accident while working at a wastewater drainage system on August 3.
According to the Gyoda Fire Department, while checking the pipeline, a person suddenly fell into a manhole about 12m deep. Three colleagues immediately climbed down to rescue but also had an accident.
All victims were around 50 years old and had been taken out of the hole and transferred to the hospital but did not survive.
The inspection results showed that the manhole contained hydrogen sulfide, a dangerous toxic gas at high concentrations. City authorities have not yet determined the initial cause of the worker's fall, and have declined to comment on responsibility in the incident.
According to Japanese police, the manhole is about 60cm in diameter, connecting to a 2.6m wastewater sewer road built in the 1980s. When the incident occurred, there were 7 workers working at the scene, their task was to check and clean up the mud if necessary.
Previously, in January, another serious incident occurred in Yashio City, when a truck driver was swallowed by a death hole due to eroded drainage pipes, causing the road surface to collapse. The victim's body was only discovered after many months of searching.
The latest incident in Gyoda continues to ring the alarm about the safety of the drainage system in Japan, forcing authorities to conduct a nationwide inspection.
