TWO Thai workers died and four were injured yesterday when a 75-tonne concrete bridge section crashed through scaffolding at a construction site in Kwai Chung. The accident happened at 3.40 pm on the troubled Kwai Chung viaduct contract. The dead and injured were taken to Princess Margaret Hospital. Srithararat Somphong, 36, died after a one-hour emergency treatment, and another unidentified worker was found to be dead at the scene. The injured workers, Namuvn Gkun, 22, Vthat Knamtan, 42, Bumsom Kuson, 34, and Phinit Czk Nok, 36 suffered broken hands or legs. They are on a one-year contract and are paid about $10,000 a month. About 100 Thai construction workers have been imported for the project. Campenon Bernard/Franki Contractors (CBF) project manager Rohan Shorland said the workers' families would be contacted and flown from Thailand. 'They all worked for the joint venture. Some of them had worked for us for years [in Thailand on similar projects],' Mr Shorland said. 'There is a technical inquiry. The segment is on the ground surrounded by scaffolding and other material. It is far too early to guess what caused it,' he said. CBF safety manager Wong Yun-yin said the scaffolding should have been able to support the weight of the segment which was being moved by special equipment. CBF and the Labour Department have launched separate investigations. The collapsed section is part of a four-kilometre elevated viaduct for airport-bound road and rail traffic being built next to the Kwai Chung container port. Mr Wong said the segment that fell was for the railway portion of the project. CBF won its $2.3 billion contract in May 1993, but the project ran into serious trouble last year after design difficulties. As a result, in December last year joint venture partner Franki Contractors said it expected to make a $645 million loss by the time the contract finished at the end of next year.