VIDEO: A tractor-trailer burst into flames Monday morning along Interstate 81 in Cumberland County. The fire happened in the northbound lanes of I-81 near Exit 37, Newville, in Penn Township just before 9:30 a.m. There were major delays as the fire raged. WGAL viewers shared a photo of the truck cab burning and other photos of traffic near the scene of the fire. Fire crews have responded. At this time, it's unknown if anyone was injured.