CUMBERLAND COUNTY – State Police in Carlisle are investigating a fatal Tuesday afternoon crash involving three vehicles on Interstate 81. It happened in the southbound lanes around 3:39 p.m. near mile marker 54 in Silver Spring Township, Cumberland County. Authorities say 35-year-old Gregory Nornhold of Mechanicsburg was driving northbound on I-81 when he crossed the grass median into the southbound lanes, and collided with a pickup truck and a car. Two juvenile passengers in Nornhold’s vehicle died from their injuries. Nornhold was taken to Holy Spirit Hospital with undisclosed injuries. The truck driver, 43-year-old Jason Flenner of Carlisle was taken to UPMC-Carlisle with undisclosed injuries. The driver of the car was not hurt.