Dramatic footage broadcast by state television showed the center of the massive steel arch giving way and plunging into the river below. According to Xinhua News Agency, the disaster was triggered when a steel cable snapped during tensioning operations.

Authorities confirmed that 15 workers and a project manager were at the site when the collapse occurred. The bridge, which was still under construction, was intended to be the world’s largest double-track continuous steel truss arch and the first of its kind to span the Yellow River.

A large-scale rescue operation has been launched, with more than 800 personnel, dozens of vehicles, 27 boats, a helicopter, and rescue robots combing the site for survivors and bodies. Nearby hospitals have also been placed on standby to receive casualties.

The Ministry of Emergency Management has deployed a special command team and opened a formal investigation into the cause of the collapse. Experts say the tragedy has once again raised questions about construction safety and oversight in China’s push for large-scale infrastructure projects.