Police say a brawl between a passenger and a bus driver was the cause of the bus plunging off a bridge in southwestern China.
An eight-second surveillance video posted by Chongqing police on its social media account shows the two got into a fight before the bus veered into the wrong lane and fell off the bridge.
A police statement said a female passenger started quarrelling with the driver after she missed her stop.
The bus collided with an oncoming car before smashing through barriers and into the Yangtze River on Sunday. Rescuers recovered the wreck of the bus on Wednesday night.
Buses in China often have surveillance cameras.
As the quarrel escalated, the statement said, the woman hit the driver on the head with her mobile phone. The driver took his right arm off the steering wheel and fought back. He grabbed her arm when she attacked him again, then hastily steered to the left, sending the bus out of control.
The Wanzhou police statement said the behaviour of the driver and the passenger seriously endangered public safety and violated the law.