Colonel Vu Chi Thuc, the Director of Quang Ninh provincial Public Security Agency said on Feb. 21 human error was likely the main reason for the sinking of a tour boat in Ha Long Bay that left 12 passengers drowned.

The initial examination showed that Do Van Thang, the chief mechanic, did not close valves that allow water to enter the boat to cool down the engine as required when the boat was at anchor.

In addition, the captain and crew had neglected their night-shift duties and as a result could not respond as water poured into the boat.

Both captain Nguyen Van Minh, 21 and chief mechanic Do Van Thang, 27, were charged and detained for “neglecting their responsibilities, causing serious damage.”

The cruise boat, the Truong Hai 06QN 5198, which belongs to the Truong Hai Company, is now at a private shipyard in Ha Long City for further examination.

The boat was built in 2008 and was scheduled for another test for the extension of its shipping registration on April 29, 2011.

There were 27 people, including 21 tourists and six crew, on board the ship at the time the accident happened at a 5 a.m Feb. 17. Nine foreign tourists and all the six crew were rescued.

Of the 12 dead victims in the accident, two were Swedes, two Americans, two Russians, one Scot, one Japanese, one French, one Swiss and one Australian of Vietnamese origin along with one Vietnamese tour guide.

The local authorities returned the bodies of the deceased to their relatives on February 19./.