Deputies responded to a domestic violence call at an apartment in the North Highlands section of the city early on Friday morning. Upon arrival, deputies say the man started a fire in the apartment.
Metro Fire arrived on scene, but said the man was no longer holding the knife. Crew members rescued the baby, an older child, a woman and the suspect from the fire.
All four were alive, and transported to a local hospital for treatment, according to deputies.
The father has been placed in custody, officials said.
Metro Fire did confirm, however, that two dogs died in the fire.