Overview

• Four men in their 50s died Saturday morning in Gyoda, Saitama Prefecture, after falling into a 12-meter-deep manhole during a sewage-pipe inspection.
• Saitama Prefectural Police confirmed hydrogen sulfide inside the shaft and suspect the workers inhaled the gas, causing rapid incapacitation.
• One worker fell first and three others plunged to their deaths attempting a rescue, police said.
• The inspection formed part of a nationwide special survey ordered after a January sinkhole in Yashio exposed corroded pipes, prompting heightened government oversight.
• Local authorities and city officials are reviewing safety protocols and emergency response procedures for aging sewage infrastructure.