State police say they are investigating the death of an unidentified 39-year-old man who ran into the path of this tractor-trailer on Interstate 79 Thursday as a possible suicide.

JACKSON TWP — An unidentified 39-year-old man died Thursday morning after he ran onto Interstate 79 and into the path of a tractor-trailer, according to state police.

Police are investigating the death as a possible suicide.

At about 7:53 a.m., the truck was traveling northbound when a man ran across the road near the Evans City exit, colliding with the tractor- trailer and sustaining massive injuries, Trooper Ron Kesten said.

The truck driver immediately called police to report the collision, and responders rushed to the scene to treat the man while troopers investigated the crash, reviewing footage from the truck’s video camera.

“The footage clearly showed the truck driver did everything possible to avoid the collision with the pedestrian,” Kesten said. “He was in the slow lane, right-hand lane ... driving at a safe speed in the lane of travel. The pedestrian ran from the east side of the road directly into his path of travel.”

Footage showed the driver immediately slowed down and attempted to swerve but was unable to avoid hitting the man, Kesten said.

“Unfortunately, there was nothing he could do to avoid the pedestrian,” he said.

Emergency responders flew the man by medical helicopter to UPMC Presbyterian Hospital in Pittsburgh where he was pronounced dead.

Investigators have not released his name, pending an investigation.

The man’s car was found parked near the scene of the incident.