Alabama police are investigating what they said was a triple homicide after two children and their mother were found dead in a home Thursday.

Police investigators in Semmes, Alabama, said the 37-year-old mother and her two children — a 6-year-old daughter and a 2-year-old son — were found dead in a residence on Evergreen Court off Snow Road in Semmes.

Police said they received a 911 call from the dead woman’s husband.

Exactly what happened or how they were killed is unclear. Local media outlets report Mobile County Sheriff Paul Burch said the two children were brutally murdered. It was not immediately clear how the mother died.

None of the victims have been identified pending notification of kin out of state.

Al.com reported that Semmes police said they had been called to the residence numerous times for domestic disputes and that a protective order from Utah was in place, though it was unclear on whom that protective order applied.