A Paulding County father says a nanny working in his home is "100 percent responsible" for the deaths of two 5-year-old girls in his family's backyard pool.

Eduardo Juarez told Mundo Hispanico his daughter was a good swimmer and may have been trying to help the other girl before both girls went under Sunday afternoon.

But neither girl should have been outside, and apparently they went into the backyard while their caregiver was on the phone, Juarez said.

Juarez said he and other family members had gone to the store to get lunch and left the two girls, including his daughter and the nanny's granddaughter, in the nanny's care.

While the housekeeper was on a 45-minute call, the girls went into the backyard, according to Sgt. Bill Gorman with the Dallas Police Department. When the family returned to the Mirage Drive home in the Vista Lake subdivision, the girls couldn't be found.

“When the family returned home, they were looking for their daughter, and her 10-year-old brother found both little girls at the bottom of the swimming pool,” Gorman said.

“The little girl who lived at the residence was a swimmer -- she could swim back and forth the length of the pool -- and the other little girl was a non-swimmer, couldn’t swim at all,” Gorman said.

“We can only speculate as to how the two of them ended up in the pool,” he said. “No one saw anything, no one witnessed anything.”

He said the girls were fully clothed.

“They were not dressed for swimming, and it was raining, so they were not supposed to be swimming,” Gorman said.

Gorman identified the girls as Sophia Juarez, who lived at the home, and Mia Penoyer of Gwinnett County, the granddaughter of the housekeeper.

He said the 58-year-old housekeeper, whose name has not been released, will be charged with reckless conduct. She was hospitalized after the incident, Gorman told Channel 2 Action News.

“It’s a tragedy, so, so sad,” Gorman said. “The little girls were so very beautiful.”

Eduardo Juarez, who also has two older children, told Mundo that his family was devastated by the tragedy.

Speaking in Spanish -- his remarks are translated -- the father said, "The nanny is 100 percent responsible for all of this. We trusted her for taking care of our daughter, and instead, she got distracted on the phone."

Juarez called his daughter a little girl with a big heart who spent Saturday at a sports event interacting with disabled children.

"Her loss will never be overcome," Juarez said.