Police say a fight 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 on Friday 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 video shows her hitting the driver across the face with her cellphone.
He then takes his hand off the wheel to punch back at her and loses control of the vehicle.
The official Xinhua News Agency said on Friday that 13 bodies have been retrieved from the river and two others remain missing.
No one is believed to have survived.
The bus collided with an oncoming car before smashing through the guardrail and plunging into the Yangtze River on Sunday.
Rescuers recovered the wreck of the bus on Wednesday night.