4 Workers Die After Falling Down Saitama Sewer Manhole During Inspection; Hydrogen Sulfide Suspected as Cause of Fall

The Yomiuri Shimbun

17:43 JST, August 3, 2025

Four male workers in their 50s died after falling down a manhole on Saturday morning at a sewer pipe inspection site in Gyoda, Saitama Prefecture.

Toxic hydrogen sulfide was detected at the scene, and the Saitama Prefectural Police believe the gas may have caused the men to lose consciousness and fall.

The city commissioned a civil engineering firm to conduct the inspection after the national government asked municipalities to check sewer lines following a January road-collapse accident in Yashio. The firm’s assignment was to examine the pipe for damage.

According to police, one worker lost consciousness while descending a ladder to inspect the sewer pipe and fell. Three coworkers who tried to rescue him also fell. All four were pulled up shortly after 4 p.m. in a state of cardiopulmonary arrest and taken to a hospital, where their deaths were confirmed.