A Columbia-area man has been identified as the driver killed when a tractor trailer reportedly crossed the median along I-77 in Chester County Thursday and hit his pickup truck. Crews at the scene said there were two vehicles involved: a tractor trailer and a pick up truck. A representative from the United States Postal Service said the driver of the tractor trailer is a USPS contract worker and en route to Charlotte from a facility in Columbia. According to troopers, the crash happened along Interstate 77 northbound near mile marker 55 around 10:09 a.m. The representative says workers are making "every effort" to recover mail that is readable and deliverable.