A mother, father, their five children and two nieces from Wylie were almost home after a family celebration in Irving Friday night when the drive lost control of his 2001 Ford Expedition.
Police said the SUV went about 500 feet off McCreary Road, down an embankment and over a dry creek before stopping at a barbed wire fence in high brush just below a bridge.
"The driver stated he believed he'd had a seizure," said Sgt. Donna Valdepena of the Wylie Police Department.
Wylie handed the investigation as the crash happened basically at the border of Wylie and Sachse in Sachse.
"The wife stated she heard the vehicle accelerate and he jumped over a creek," said Sgt. Valdepena.
Two helicopters, PHI and Careflite rushed three of the children to Children's Medical Center in Dallas. Ambulances rushed four others to area hospitals. The mother and father were not seriously hurt.
"The first responding officer said he couldn't find the vehicle," said Sgt. Valdepena. "He turned his siren off and he could hear the screaming so he went down into the darkness and found the vehicle just beyond the creek."
Police shut down about a mile of McCreary Road off FM 544 for more than six hours Saturday morning before getting a crew to remove the SUV.
The injured children's ages range from 6 to 14-years old. Police say a 14-year old girl has life-threatening injuries.