PITTSBURGH (KDKA) — The driver of a tri-axle truck has been rescued after the vehicle plunged over a hillside late Wednesday morning in Squirrel Hill.

The truck crashed around 10:45 a.m. at the intersection of Serpentine Drive and Bartlett Street, and dropped about 50 feet over a hillside. It happened in the Panther Hollow area of Schenley Park.

(Photo Credit: NewsChopper 2/KDKA)

(Photo Credit: NewsChopper 2/KDKA)

Trees were holding the truck in place as emergency crews arrived on the scene.

It took emergent crew one hour to stabilize the vehicle before they could rescue the driver.

“From initial reports, it appears part of the hillside gave way, and again, they’re doing work on the roadway. They’re milling it and repaving it,” Pittsburgh Police spokesperson Chris Togneri said. “We’re not sure what caused the vehicle to go over. We’re not even sure if it was moving or stationary at this point, but it was fully loaded with asphalt.”

City officials say the truck was actually part of private contractor crew that was working on the repaving Serpentine Drive.

The driver was pulled from the truck by medics who scaled the hillside. He was conscious and talking, but complaining of back and shoulder pain. He was taken by ambulance to UPMC Presbyterian Hospital in stable condition.

WATCH: NewsChopper 2 flies over the scene —

Crews then began work to pull the truck up from the hillside. Large equipment was on the scene to aid the workers.

The road was closed while crews worked to clear the scene. Park rangers also closed a trail below the hillside to prevent hikers from entering the area.

No word on when Serpentine Drive will reopen to traffic as the road is still unsafe, according to police.

(Photo Credit: Brenda Waters/KDKA)

Police are investigating the cause of the crash.