OKAYAMA – Five workers went missing Tuesday afternoon after an undersea tunnel caved in and seawater gushed in at JX Nippon Oil & Energy Corp.’s Mizushima oil refinery in Kurashiki, Okayama Prefecture, the company said.
Police divers searched for the missing workers after the incident was reported to the fire department at around 12:35 p.m. They suspended the search shortly after 3 p.m. because of poor visibility and dangerous debris.
Dark, muddy water littered with debris filled the vertical entrance shaft as emergency workers looked on.
The company believed there was only a slight chance the trapped five were still alive.
“It’s difficult . . . ,” a JX Nippon official repeated when asked whether the missing workers could be found safe.
JX Nippon identified three of the five as Yoshinobu Fuchihara, 61, Mitsuteru Miyamoto, 39, and Katsuhito Koara, 47. They are employees of the Koshin Kensetsu construction firm based in Chita, Aichi Prefecture.
The other two, Haruji Matori, 43, and Akihiro Minamitsubo, 57, are employees of Tokyo construction firm Koei Kengi.
The tunnel, which is under construction and will ultimately be U-shaped, has an opening measuring 11 meters in diameter and its vertical section is about 30 meters deep, the company said. At the bottom of the shaft, the tunnel bends and runs parallel with the surface for several hundred meters before it connects to the other vertical shaft.
The missing men are believed to have been working in the horizontal section some 140 meters from the vertical shaft, the company said.
Another worker, Kenji Kakui, 61, who was working at the bottom of the vertical shaft separately from the trapped five, managed to float to the surface as the seawater gushed in, the company said.
Kakui tried running up the spiral stairs on the vertical shaft after hearing someone shout, “Watch out! Run!” But he was eventually caught in the surging water.
“It came rushing to me in a matter of a second,” Kakui was quoted as telling rescue workers.
The tunnel has been under construction since 2010 for a pipeline linking two plants, with its completion scheduled for 2013.
In Chita, Koshin Kensetsu officials were worried about the safety of its three workers.
The construction firm received the first report of the accident at around 1 p.m., an official said. No updates came from the refiner after that, he added.
According to the official, Koshin Kensetsu began digging the undersea tunnel last September in what is known as the shield tunneling method.
“All of them are veteran workers with a lot of experience in tunneling work,” the official said. “We can only wait for good news.”