Cobb County police say the accident near Marietta occurred on Sunday when a Porsche crossed the center line and swerved, striking a minivan carrying Alison Barnes Salter and her daughters. Atlanta Medical Center spokesman Marcus Gordon said Mario D. Zuniga, the driver of the Porsche, died Monday at the hospital.
Salter, an attorney in her father's firm, was treated for arm and foot injuries and released at Kennestone Hospital. Her daughters were taken to Scottish Rite Hospital in Atlanta. The 6-year-old, Lilly, was treated and released. The 4-year-old, Ella, was to undergo surgery to place a pin in a broken arm.
Police say Zuniga's 16-year-old passenger was taken to Kennestone with non-life threatening injuries.
The Barnes family said Barnes' daughter had been running errands when the accident occurred.
"This is every parent's and grandparent's worst nightmare," Barnes spokeswoman Anna Ruth Williams said in a statement. "Roy and Marie extend their deepest sympathies to the Zuniga family and their thoughts and prayers are with them as they deal with this tragic loss."
Barnes issued a statement thanking first responders, hospital personnel and well-wishers. He canceled campaign appearances until further notice.
His Republican opponent, Nathan Deal, issued a statement late Sunday.
"As fellow parents and grandparents, Nathan and Sandra are keeping the Barnes family in their thoughts and prayers tonight. They are saddened to hear of the injuries and hope for speedy recoveries for all involved."