MANSFIELD, PA. (WENY) -- A massive fire engulfed a tractor-trailer in the Northern Tier early Thursday morning. 

The incident reportedly began around 3:45 a.m. on Route 15 heading northbound in Mansfield. 

According to WENY-TV's reporter on the scene, Mansfield and Lawrenceville Fire Departments were attending to the fire. The reporter also mentioned it looked as though the truck tractor was unhooked from the semitrailer, which was the actual part that was on fire. That information, however, is still unconfirmed at this time. 

It is unclear how exactly the fire started, and no injuries are known at this time. 

This is a developing story, and WENY-TV will be sure to update you on any new information as it comes in.