In February, a freight van carrying fireworks that was driving on the highway viaduct in Sanmenxia exploded, causing the viaduct to collapse, China's state-run Xinhua News Agency reported Friday.
Following its investigation into the incident, the Henan Provincial Work Safety Bureau urged authorities to hold 43 people accountable.
Prosecutors in Sanmenxi in July charged 20 people from the firecracker manufacturer and transport companies in the case.
The bureau's report did not address public concerns related to the construction integrity of the viaduct. Many online users have suggested possible corner-cutting led to the viaduct's vulnerability to explosion.