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.