建設中のハイパーカミオカンデで配管事故　作業員5人が重軽傷 [岐阜県]：朝日新聞

This page reports a pipe accident at the Hyper-Kamiokande facility under construction in Hida, Gifu Prefecture. On March 31, 2026, during pressure inspection in a tunnel, a vinyl chloride pipe detached at its joint and ruptured, forcefully releasing air that injured five male workers aged 20-60. Two workers suffered serious injuries while three sustained minor injuries; all remain conscious. Hyper-Kamiokande, the third-generation facility following the Nobel Prize-winning Kamiokande, aims to begin operations in 2028. The world's largest artificial rock cavern, measuring 69 meters in diameter, was completed last year and will serve as a neutrino research center.