Two Williamsburg County children were killed after a car their mother was driving overturned in a field Saturday afternoon.

The crash happened around 2:10 p.m. Saturday, on S.C. 261, six miles east of Kingstree, said Cpl. Paul Brouthers with the S.C. Highway Patrol.

A passerby saw the overturned car and called for help, said Vernal Fulton, deputy coroner for Williamsburg County.

The driver of the car, Tami Yvette Turner, 40, was almost thrown out of the van from the impact of the crash, Fulton said.

She told officials investigating the accident that she was wearing a seat belt, Fulton said.

Her daughter, Tamaya Burgess, 10, was thrown from the vehicle after it overturned in a field.

The S.C. Highway Patrol Web site said the child was not wearing a seat belt.

Turner could not immediately find her daughter after the crash, Fulton said.

She did manage to free her son, Tamal Watson, from the wreckage. He was not wearing a seat belt, according to the Highway Patrol.

Tamaya died at the scene, investigators said.

Tamal was taken by helicopter to McLeod Regional Medical Center in Charleston.

He died around 8 a.m. Sunday, Fulton said.

The Highway Patrol said Turner was driving on the rural road when she lost control of her vehicle around a curve.

Her 1999 Windstar van overturned after it veered off the road, troopers said.

The crash remains under investigation.