Fireworks in a cargo truck exploded on a highway bridge in Henan yesterday morning, killing at least nine people and bringing down an 80-metre section of bridge.
The truck and seven other vehicles, including a truck loaded with 10 cars, fell more than 30 metres into a dry river in Mianchi county, local authorities said.
The victims were taken to several hospitals in the nearby city of Yima . Xinhua said seven were killed at the scene and two died on the way to hospital. By 9pm, 11 people were listed as injured, with four in serious condition, a provincial official news portal reported, citing the rescue command at the scene.
There were conflicting reports on casualties and the cause of the accident. An early report on state radio put the death toll at 26. By evening, state television speculated whether the bridge had collapsed first, triggering the blast .
But late last night the rescue command said an initial investigation suggested the blast caused the collapse, but they were still trying to determine what set off the explosion, Xinhua said.
Investigators from the Ministry of Public Security and State Administration of Work Safety had been sent from Beijing to investigate, state TV reported.
Search and rescue efforts were complicated by the difficult terrain and huge amount of wreckage.
The builder of the bridge, Henan Expressway Development, faced questions about its quality. Many internet users asked how a large, modern bridge could be destroyed by fireworks.
Professor Jiang Zonglin , of the Chinese Academy of Sciences' Institute of Mechanics, said if all the fireworks exploded at the same time or in quick succession, they would have enough power to bring down a bridge, especially at a structurally weak point.
"The final conclusion must be made from a thorough examination of the truck's wreckage to determine the strength and direction of shock waves, but it is definitely possible to destroy a bridge with so many explosives."
China Central Television reported this week that more than 60 per cent of fireworks trucks on the mainland did not have proper licences or permits to transport hazardous materials. They lacked protective containers and few drivers were aware that some fireworks contained chemicals that would catch fire even if they were in contact with water.
Such accidents happen almost every year. Four people died in an explosion on a highway in Anhui province in March. Yesterday's accident occurred on the 4,300-kilometre G30 expressway, China's longest.