Hutchinson police say a 14-year-old boy is in custody after a fire at his home killed his mother and sister.

Police say the boy is suspected of deliberately setting the fire on Thursday. The teenager has not been charged.

District Attorney Keith Schroeder says investigators determined an accelerant was poured in several rooms on the first floor of the house and intentionally ignited.

Fire officials say the mother and daughter were found dead together in a bedroom. The girl died shortly after the fire and her mother died later Thursday.

The boy and his father were unharmed.