A lawsuit has been filed against the U.S. government on behalf of a 15-year-old girl who saw her grandmother killed in the fiery crash of an Army ambulance transporting the two to a hospital.

Wallace F. Nelson, guardian and grandfather of Amanda Nelson, contends the girl suffered post-traumatic stress from the July 1988 accident in Tooele County.The $416,500 lawsuit, filed in U.S. District Court for Utah, asks for more than $66,500 to cover medical, psychiatric and special education expenses and general damages of $350,000.

The girl was being taken by ambulance to Primary Children's Hospital in Salt Lake City after she was injured in a bicycle mishap at Dugway Proving Grounds, the suit said.

Her grandmother, Lois Nelson, was with her in the ambulance, which was traveling in excess of 80 mph when it sped off a highway in Skull Valley, rolled several times and burst into flames, killing Nelson, according to the suit.

The child, restrained on a stretcher in the ambulance, received minor injuries but still suffers from stress after seeing her grandmother killed, the lawsuit contends.

The Nelsons had been raising the child and two of her siblings since the girl's mother, Robin Nelson, was disabled in a car accident in 1983.