A CHILD has tragically died and another has been injured after a quad bike crash near Pilliga on Sunday. Five children, aged between five and 13, were riding two quad bikes on a rural property when one of the vehicles, carrying three children, left the private roadway and struck two trees about 12.15pm. A six-year-old girl died at the scene. A 13-year-old girl suffered head injuries and was flown to Sydney. Police are investigating all circumstances, including if any of the children were wearing helmets.