On Saturday June 19, Mary Giedeman had just let her dog out and began working in the kitchen of her Grove City, OH, home when she quickly noticed an eerie silence.  

She immediately began searching for her 2-year-old daughter Carmella.

Carmella was face down in the family's above-ground pool. 

Giedeman got Carmella out of the water and placed her on the deck. 

But she didn't know what to do next. She didn't know how to perform CPR, she told the Columbus Dispatch .

At that exact moment — five houses down —off-duty Columbus police officer Brian Wilson was getting out of the car.

Wilson heard Giedeman's screams. He and his wife, Holly, ran toward the cries for help. They discovered Carmella and Giedeman on the deck. 

Wilson said Carmella's face and lips were blue, and he couldn't feel a pulse. He immediately began performing CPR. 

Finally, Carmella vomited and began taking shallow breaths. 

The medics arrived and began conducting their own work to save Carmella, but one thing was clear. 

"She would not be here if it weren't for him," Giedeman said.