The bodies of four tunnel workers missing since Thursday following an explosion some 1.2km into a 2.8km long tunnel under construction in Minamiuonuma, Niigata Prefecture, Japan were located and recovered in a rescue operation on Sunday morning, according to local firefighters.
Rescue attempts were put into action immediately after the explosion at around 10.30am last Thursday, but high levels of flammable gas hampered operations later that night. The four bodies were finally discovered at 1.15am on Sunday but high gas levels made it impossible to retrieve them until after 6am.
The four, have been identified as Daisuke Kobayashi, 37, an employee of Tokyo based contractor Sato Kogyo Co which was building the tunnel, and Kokichi Koshii, 57, Takafumi Toda, 40, and Masayuki Otani, 39, all working for a subcontractor.
Local press reports say police searched the office of Sato Kogyo’s Hokuriku branch in the city of Toyama in Toyama Prefecture on Sunday morning and two other places on suspicion of professional negligence resulting in injury.
Further local reports say the deceased tunnellers were preparing to resume work on Thursday morning following a winter break. The infrastructure ministry has said the tunnel alignment had been changed to avoid methane heavy geological strata.
The tunnel is scheduled for completion by December.