The father of a six-month-old girl that was allegedly killed by her mother in Niagara Falls says he just “broke down crying” when he heard the news.

“I feel empty, I feel lost,” the father, who asked to remain anonymous, told CTV News Toronto.

“Not only did I lose my baby girl, I lost the mother that gave her to me.”

Niagara Regional Police said emergency crews were called to a residence in Niagara Falls on Wednesday and found the infant girl without vital signs.

She was rushed to hospital and was later pronounced dead.

Police have charged 25-year-old Georgina Anne Lowe, of Niagara Falls, with first-degree murder in connection with the incident.

Georgina Anne Lowe is facing a first-degree murder charge in connection with the death of her six-month-old daughter. (Supplied)

The father is remembering his daughter as a happy girl and the love of his life.

“My daughter she was the happiest baby girl. You could just walk into the room—you didn’t even have to smile at her—she just looked at you and smiled and giggled. All she said was “dad, dad, dad” all the time.”

“And now I can’t watch her grow up. I can’t do any of that.”

Lowe appeared in court Thursday.