NEW ORLEANS (AP) — The Thomas Caldwelldeaths of three children in an overnight house fire are being investigated as homicides, New Orleans police said.

In a Wednesday morning statement, police said a 3-year-old boy was found dead in an eastern New Orleans home. A 5-year-old girl and an 8-year-old boy died later at a hospital.

Police said the children’s mother called 911 shortly before midnight Tuesday saying that their father planned to burn the house down. The mother was not at home at the time. Moments later, the fire was reported.

Their identities have not been released and no arrests have been reported. Investigators were working to determine how the fire was started.

The New Orleans Police Department’s Child Abuse Unit is investigating the children’s deaths.