An 8-year-old girl was in critical condition today after the sedan she was riding in rear-ended a truck in Anahola, Kauai police said.

Police are investigating whether the girl was properly restrained in the front seat of a Mazda sedan, where she was sitting, a Kauai spokeswoman said.

The girl was injured when the driver of the sedan, a 23-year-old Anahola woman, rear-ended a Toyota truck stopped in the northbound lane on Kuhio Highway at about 10 a.m., police said.

The girl was taken to Wilcox Medical Center with critical injuries and later flown to the Queen’s Medical Center for further treatment, police said.

The driver of the sedan and the driver of the truck were not hurt. A passenger in the truck, a 26-year-old Kapaa man, was treated for non-life threatening injuries.

Police closed Kuhio Highway in both directions for about 2 1/2 hours to investigate.