Two bodies -- of a Korean man surnamed Ahn and a man from Myanmar -- were found at 5:42 a.m. and 5:47 a.m. Thursday, respectively, some 200 meters from the scene of the rescue operation.

A report that three workers were isolated at the construction site was filed at 8:24 a.m. Wednesday.

Two of the men -- both working for a subcontractor of Hyundai Engineering & Construction -- reportedly went down the water pipe located 40 meters underground for a routine inspection at around 7:10 a.m. Rain started to pour and Ahn -- an employee for Hyundai Engineering & Construction -- went in about 40 minutes later to evacuate them. However, the entrance was soon blocked at around 8:10 a.m. by rainwater rushing into the facility, and the workers could not exit the pipe, according to officials at the accident scene.

The 3.6-kilometer-long, 10-meter-wide drainage pipe automatically opens and closes when it reaches 70 percent capacity. A test-run of the facility, built by Hyundai Engineering & Construction, began in April and was to be completed in December.

An official in charge of the construction was quoted as saying that the accident resulted from the unexpectedly heavy downpour. The workers went ahead with the operation despite the weather forecast, which critics say resulted in the “manmade” disaster.

There was neither safety equipment in the tunnel nor were there ways to contact the workers inside the pipe. 

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)