Kortni Peek, 26, was about a half-mile from her home in Indiana when she lost control of the car on a sharp curve last week with her daughters -- 8-month-old Maggie and 2-year-old Ella Rose -- inside.
"I was just the most scared I've ever been," Peek told The Early Show Monday.
Peek said the ordeal felt like it happened in slow motion, though it was her quick actions that saved the day.
She said she unstrapped her daughters from their car seats, pulling them to the front seat. Peek then left the car through the driver's side window to see how deep the water was - 8 feet, she said, then came back and retrieved her daughters and carried them out through the window.
Water safety expert Gerald Dworkin, a consultant for Lifesaving Resources, Inc., praised Peek's heroics and emphasized the importance of acting quickly in similar situations.
"Once the vehicle hits the water, you only have between 30 seconds and several minutes to make your escape," he said.
For more survival tips, watch the video below:
To see the interview with Peek, watch this video: