A woman locked her husband and three-year-old baby in their house before setting it on fire on Monday.
Police said Dorris Miriam, 19, and Daniel Mwangi, 30, had a serious disagreement before they retired to bed the previous night.
They lived at Methi village in Maragua, Murang’a county.
Beth Nyambura, Mwangi’s grandmother, said neighbours took long to break into the house as the woman hid the keys.
“I heard the screams of my grandchild and called neighbours who responded immediately,” she told journalists at the scene.
Maragua OCPD John Onditi said preliminary investigations indicated Miriam set the house on fire in an attempt to kill her family.
The woman and her husband died at Kenyatta National Hospital where they were rushed by neighbours while the child was admitted with serious burns.