State police say a driver was killed when his vehicle rear-ended a tractor-trailer on a major highway in Hunterdon County, a crash that also left a child injured.

The crash occurred around 8:45 a.m. Friday in the westbound lanes of Interstate 78 in Clinton. The vehicle was crushed underneath the truck, and the driver was pronounced dead at the scene.

The child was a passenger riding in the car's backseat. But further information has not been released on the child’s age or the extent of injuries.

Troopers shut down all westbound lanes on the highway in the area of the crash, causing travel backups that stretched for about 5 miles at times. Authorities said rubbernecking delays were also occurring on the eastbound side.

All lanes have since been reopened.