Four workers died after falling into a manhole Saturday during a sewage pipe inspection in Saitama Prefecture, north of Tokyo, police said.
Authorities received an emergency call at around 9:25am (GMT +9) after one man apparently fell into the manhole in Gyoda, followed by the other three who tried to rescue him, reports Kyodo News.
The four men, believed to be in their 50s, did not respond to calls after falling into the manhole, measuring about 60 centimetres wide and 12 metres deep. With hydrogen sulfide –a highly toxic, colourless gas – detected around the accident site, police are investigating whether the gas was connected to the fatal incident.
The manhole is connected to a 2.6 m-wide sewer pipe, which was installed in 1981. At the time of the accident, about seven workers commissioned by the city government were conducting drainage work in preparation for the inspection.
The central government has asked municipalities to carry out emergency inspections of their sewage systems in the wake of a massive sinkhole that appeared at an intersection in Yashio, Saitama Prefecture, on January 28 this year.
A city official said the inspection was being conducted following the appearance of the sinkhole that swallowed a truck and its driver, whose body was recovered in May.
The incident, believed to have been caused by sewer pipe corrosion, drew public attention to sinkholes and prompted the government to focus on measures addressing aging infrastructure. The government’s probe launched in March has focused on sewer pipes with a diameter of 2 metres or larger that were installed at least 30 years ago across the country.