Investigators are trying to determine whether a Japanese contractor consortium or designers with the transport ministry of Vietnam were to blame for the fatal Sept. 26 collapse of a 90-meter-long section of a cable-stayed bridge, which was under construction near the southern city of Can Tho.

Ap/Wideworld Collapse of bridge section during construction has killed at least 50 workers

At least 50 people have died and more than 80 injured when the section of the $343-million, 2.75-kilometer-long cable-stayed bridge over the Hau River buckled and crashed 30 m to the ground. A consortium of Taisei Corp., Kajima Corp., and Nippon Steel Corp., with consultant Nippon Koei-Chodai (TKN), began work in 2004 with completion slated for next year. Japanese loans are financing the bridge.

TKN may find it difficult to escape severe censure from the governments of both Vietnam and Japan if found culpable. Vietnamese media have published a  June 27 memo by structural specialist Hiroshi Kudo, in which he urged the TKN consortium to “reinforce immediately” the support scaffolding for the  project. Chu Ngoc Sung, an expert at the Hanoi Sciences and Techniques As­sociation, says a section of bracing broke and brought down everything with it. Nguyen Ngoc Long, director of work quality assessment and management for the government, has blamed the contractor for poor supervision of dozens of subcontractors.

Some suspect that ministry designers may have failed to accurately calculate the load-bearing capacity of the pylons for freshly placed, wet concrete. Nguyen Van Cong, Ministry of Transportation spokesman, says earlier heavy rain softened the earth, possibly causing the pylons to settle and tear down the bracing for the freshly poured spans.