SUMMERVILLE, S.C. (WCBD) - The Charleston County Sheriff's Office is investigating a fatal crash involving a semi-truck on Hwy 78. Officials say the two-vehicle collision, involving the semi-truck and another vehicle, occurred on Hwy 78 near Poplar Grove Place in Summerville. Deputies reported the crash just after 5 a.m. Deputies say the vehicle involved was traveling at a high rate of speed when it collided with the tractor-trailer. Through an initial investigation, deputies determined the semi-truck was pulling out of Hwy 78 heading west when it was struck by the other vehicle. The driver of the vehicle was entrapped and later pronounced dead at the scene. Hwy 78 remained closed in that area for several hours. All lanes have since reopened. There is no additional information on the deceased.