According to reports with Bartow EMS, the accident occurred around 6:30 p.m. on I-75 at Highway 20.  A tractor trailer and several passenger cars collided shutting down the highway.  Brad Cothran with EMS said, upon arrival crews found a five month old baby in a car seat unconscious and weak.  The mother was also unconscious and unresponsive due to numerous injuries including respiratory issues.  Both were treated with advanced life support measures and transported to Kennestone Hospital.  Life flight was considered for transport but prohibited by weather conditions.  The driver of the tractor trailer was transported to the Cartersville Medical Center with minor injuries.