KANSAS CITY, Mo. (AP) — Kansas City police are investigating after a 2-year-old girl was found dead from burn-related injuries at an apartment.

Officers say they got involved after an ambulance was dispatched to the residence Thursday afternoon. They found the girl already dead, and a 4-year-old boy with burns to his chest and back.

The boy was taken to a hospital, where he is in serious condition.

Police say there’s evidence a fire occurred inside the apartment at least 12 hours before the ambulance was called.

Authorities say the children’s mother, a 9-year-old child and an 11-month-old baby also were inside, but had no obvious injuries.