It happened around 7:10 a.m. on Brassfield Road, near Pope Road, east of Creedmoor in Granville County.
Troopers said the girl's father - Keith Gardner - was on his way to the First Baptist Academy in Creedmoor to drop his daughter Kamryn off at daycare.
Gardner hit a deer and lost control. His car went off the left side of the road and hit some trees before landing upside down in a creek swollen by recent rain water.
The car was partially submerged and Gardner struggled in vain to get his daughter - who was strapped into her car seat - out of the car.
Other motorists arrived and tried to help. After about 20 minutes, they managed to lift the car right side up and got the child out.
They began CPR, but Kamryn Gardner was pronounced dead at Duke Hospital. Keith Gardner was also at the hospital. There's no word on his condition.
"Three years old - it's a tragedy, very sad. I've got a couple kids myself, eight-year-old and one's five-months-old. And it's just, tears you up inside. Something you won't forget," offered R.B, Britt with the North Carolina Highway Patrol.
ABC11 has learned that father and daughter - born in August, 2007- are the family of Assistant Granville County District Attorney Tasha Clay-Gardner.