Video shows a bus falling from a bridge in St. Petersburg, Russia, killing seven people

A bus veered through traffic, veered off a bridge and plunged into a river in St. Petersburg, Russia’s second-largest city, on Friday. According to officials, seven people were killed.

The Investigative Committee, Russia’s leading criminal investigation agency, reported the death toll. It did not say how many others were injured, but the Emergencies Ministry had previously said six people removed from the bus were in critical or serious condition.

According to Russian news, 15 to 20 people were on the city bus when it broke a barrier and plunged into the Moika River in central St. Petersburg. Six of those on board climbed out of the water on their own.

Surveillance video released by Russian media showed the bus traveling at high speed, turning sharply onto the bridge, swerving across the lane and colliding with another vehicle before breaking through the barrier and falling into the water.

A witness described passers-by jumping into the water to help rescue the passengers.

“They just jumped in with their clothes on and helped,” she said in Russian.

Authorities in St. Petersburg said the owner of the bus was fined 23 times for various violations. Most of the city’s bus services are operated by private companies.

Another witness said it appeared as if “he was either steering erratically or the brakes failed.”

The bus driver was arrested by the police. His wife was quoted by Russian media as saying that managers forced him to work a morning shift after he had worked 20 hours the previous day and had virtually no rest.

Authorities launched a criminal investigation into alleged traffic violations and unsafe travel services.