Officials at Aiken County Public School District placed a bus driver on paid administrative leave following a May 27 collision.
Barbara Moore, 51, was driving a school bus that collided with a tractor-trailer on Beech Island Avenue.
The wreck killed Kyrie Henry, 4, and injured another preschool student, Michayla Brown, according to Highway Patrol Lance Cpl. Judd Jones.
"The driver has been placed on administrative leave," said Merry Glenne Piccolino, the public information director for Aiken County Public Schools, adding that it is normal protocol following an accident.
Moore has been an employee since September 2011 and has had no previous history of accidents or violations, Piccolino said.
It was unclear how long the leave will last.