It happened Monday afternoon on LA Hwy. 9 in Natchitoches Parish.
State Police Troop E tells KSLA News 12 three year old Tyler Nelson was killed when the car he was riding in crossed the center line in a curve and hit an 18 wheeler.
All indications show Tyler was not properly restrained in the car.
The driver of the car, Billy Ray Nelson, was flown to LSU with critcal injuries.
The driver of the 18 wheeler suffered minor injuries.