MONTGOMERY COUNTY, Pa. (CBS) – A driver was killed Friday morning in a freak accident on the Pennsylvania Turnpike.

It happened on the eastbound lanes of the Pennsylvania Turnpike, near mile marker 355.6, in Montgomery County.

Just after 9 a.m., police say the driver of a tractor-trailer struck a piece of debris on the westbound lane which flew over the center concrete barrier, striking another driver in the head.

Police say Gregory Leiber, 57, of Langhorne died at the scene

It remains unclear what debris struck the driver.

The incident remains under investigation.