The Newton County coroner arrived at the scene to determine how the child died.
Neighbors said they are left stunned. They told WSB-TV that they never imagined the sweet child they saw playing and walking the street with her family would be the center of a death investigation.
The situation alarmed neighbor Jackie Kendrick.
"I did not expect to come home and see this in my community. I'm really sorry about that, and it breaks my heart. This was a baby, a 2-year-old baby, so it's devastating," Kendrick said.
Around 5:30 p.m., deputies rushed to the scene of what they called a penetrating trauma. An hour later, they said the coroner pronounced the girl dead.
Deputies said they detained the mother because she was in the house when the incident happened.
Kendrick said she walked around the neighborhood with the little girl, her mom and her grandma from time to time.
"She's so happy and always bubbly, every time I see her," Kendrick said.
Kendrick said nothing seemed out of the norm.
"They're all out walking and seemed to be just a happy family," Kendrick said.
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Michael Robinson lives next door to the child's grandparents. He said they couldn't be better neighbors. Robinson often saw the girl riding in her automatic car or swimming in the pool.
"Just a typical little girl having fun all the time. I would hear her over there splashing in the water," Robinson said. "I just saw the little girl yesterday and the mom, and I'm always waving to the grandparents, so it's just unthinkable."
Deputies have not confirmed how the child died or whether the mom is a suspect. They said an upcoming autopsy by the Georgia Bureau of Investigation will lead to more answers.