MCCANDLESS TOWNSHIP, Pa. (KDKA) – A deadly multi-vehicle crash involving a Port Authority bus temporarily shut down McKnight Road.

PennDOT says a multi-vehicle crash on McKnight Road northbound closed the entire road to traffic between Arcadia Drive and Cumberland Road in McCandless Township.

(Photo Credit: KDKA)

KDKA’s Shelby Cassesse reports from the scene that one man died. His car rear-ended a Port Authority bus while the bus was making a scheduled stop.

A spokesperson for Port Authority says the driver was pronounced dead at the scene.

The Allegheny County Medical Examiner identified the man as 50-year-old Anthony John Diulus of Pittsburgh.

Police say it is not clear how the victim died.

WATCH: KDKA’s Shelby Cassesse Reports Live From McKnight Road.

“We don’t know yet if it was a medical emergency or the result of the crash,” said Ryan Hawk, acting chief of the McCandless Police Department.

The bus, the O12-McKnight Flyer, was carrying about a dozen passengers and heading outbound at the time of the crash, Port Authority says. One passenger was checked by medics at the scene and then released.

One passenger was defaulted for injuries and released.

Police are investigating.

McKnight road has since completely reopened to traffic.

This is the second fatal crash involving a Port Authority Bus in less than a week.

Over the weekend, a Pitt student was struck and killed by a bus.