ON 09/11/2019, AT APPROXIMATELY 6PM, WE WERE TRAVELING NORTH ON WV SR2 NORTH APPROXIMATELY 2.5 TO 3.0 MILES NORTH OF THE SR2 I-77 INTERCHANGE. 2017 FORD EXPLORER WAS STOPPED, WAITING ON OPPOSING TRAFFIC TO CLEAR, IN ORDER TO MAKE A LEFT HAND TURN INTO THE PARKING LOT OF CHURCH. VEHICLE WAS REAR-ENDED BY A DODGE DAKOTA PICKUP TRUCK IMPACTING SLIGHTLY OFF CENTER TOWARDS THE DRIVER SIDE OF THE VEHICLE. THERE WERE 4 OCCUPANTS OF THE EXPLORER. THE DRIVER WAS A 39 YEAR OLD MALE. THE FRONT PASSENGER WAS A 36 YEAR OLD FEMALE. IN THE SECOND ROW WERE THE OTHER 2 PASSENGERS. ON THE DRIVERS SIDE WAS A 4 YEAR OLD FEMALE, FORWARD FACING IN A GRACO EXTEND2FIT CAR SEAT. THE PASSENGER SIDE WAS OCCUPIED BY A 7 YEAR OLD MALE IN AN EVENFLO BOOSTER SEAT. ALL PASSENGERS WERE WEARING APPROPRIATE RESTRAINING DEVICES. ALL PASSENGERS WERE SHAKEN UP, WITH EXTERNAL INJURIES TO BOTH DRIVERS SIDE OCCUPANTS. THE PROXIMATE CAUSE OF THE INJURIES WAS DUE TO FAILURE OF THE DRIVER'S SEAT. THE SEAT BASE EXPERIENCED A FAILURE CAUSING THE SEAT BACK TO FALL BACK ONTO THE 2ND ROW PASSENGER, STRIKING THE PASSENGER, AND THE HEADREST BENT AND PARTIALLY DETACHED. PRIOR TO THE ACCIDENT, THE SEAT BACK WAS FULLY UPRIGHT AND THE SEAT WAS RESTING UPON THE LEGS OF THE JUVENILE FEMALE AFTER IMPACT. SHE SUFFERED CONTUSIONS TO HER LEGS FROM THE SEAT IMPACTING HER AND SHE SUFFERED A CONCUSSION AND LACERATION (REQUIRING 9 EXTERNAL SUTURES AS WELL AS SOME INTERNAL ONES) ABOVE HER RIGHT EYE, CAUSED BY EITHER THE HEAD OF THE DRIVER