One person was killed and five others were injured in a bus accident Friday night on the New Jersey Turnpike in Mercer County, authorities said.

Just after 8:40 p.m., the bus was involved in a crash near Mile Marker 57 in Hamilton, said Sgt. Lawrence Peele, a state police spokesperson.

Peele confirmed that one person had died in the crash, which occurred in the southbound outer lanes.

The bus driver was trapped and required extrication, according to a tweet posted by the union representing some of the firefighters responding to the scene. The union said that five people had been injured. There was no immediate word on the condition of the bus driver.

It was unclear how many vehicles were involved and how many of the injuries were on the bus.

The outer southbound lanes remained closed as of 10:20 p.m., Peele said. The cause of the accident was under investigation.