According to Vietnam officials a bridge under construction collapsed Wednesday, killing at least 52 workers and injuring 97 others.
The Japanese-funded bridge was being built across the Hau River, a branch of the Mekong River, in the southern city of Can Tho. It is part of a heavily traveled route that links the Mekong Delta and Ho Chi Minh City.
At least 52 people were dead and 97 others were injured, said Le Van Ut, the vice chief of police in Vinh Long Province.
Rescue teams were digging through the rubble in search of survivors, said Le Viet Hung, vice chief of the Can Tho police. "It was total chaos," he said. "It sounded like a huge explosion. It's the biggest accident I've ever seen."
The exact number of missing was unknown, but officials said at least 200 people were working on the 100-meter bridge section when it buckled at about 8 a.m.
Officials were still investigating the cause of the accident.
Cement had been poured into the collapsed section just one day earlier, on Tuesday.
The bracing supporting it had apparently weakened, said Pham Van Dau, chairman of Vinh Long people's committee.
Construction of the span, which was not open to traffic, was being overseen by Japanese companies Taisei Corp., Kajima Corp., Nippon Steel Corp. and Nippon Koei-Chodai.