According to The China Daily, 6,300 bridges have been categorised by the government as dangerous because of structural damage.
Xiao Rucheng, secretary general of China's Institute of Bridge and Structural Engineering, was quoted as saying that many of the country's new bridges were being built too quickly and were poorly designed. Other architects said there may be more accidents now, but the main reason is that there are more projects.
It seems that the Chinese have really let their craftmenship slip, its a shame really, the really dont need more attention added on to the whole toothpaste, lead paint thing either.

Most of the workers were local farmers, supplementing their incomes by labouring on the bridge, which was designed to improve transport links in Fenghuang - a popular tourist spot
Also, like P4B said Best wishes to families of these workers, who were just trying to get by