An eleven-year-old boy has died from injuries sustained when a go-cart he was in collided with a car. Zackery J. Stephens of Greenbrier died Monday afternoon at Arkansas Children`s Hospital following an accident Sunday evening in Greenbrier. Police say 16-year-old Mark Welter was also in the go-cart and was in stable condition Monday at the hospital. The collision occurred as the go-cart pulled onto a street, police said. The accident remains under investigation. Police said it was still unclear which boy was driving the go-cart.