TULSA, Oklahoma - Police say a mother and grandmother could face charges in a Tulsa house fire last week that killed 18-month-old Carabelle Douglas.

Police say baby Carabelle should never have been at the house that night with her mother, because her mother has a meth problem and lost custody of her little girl. Carabelle's grandmother had guardianship but police say the grandmother decided she needed a night out on the town.

Police say the grandmother chose to let Carabelle's mother babysit the girl, even though the courts had said the mother was not fit to have custody.

Police say Carabelle and her mother were sleeping together in the little girl's room when a fire started. The fire department said the fire started in or near the that room.

"She did admit to using meth earlier in the day but denied using meth in the room with the kiddo that night,” said TPD Child Crisis Cpl. Mark Kraft.

Police say the mother broke a bedroom window and got out with a few cuts on her arms and some smoke inhalation, but she didn't take the baby with her.

Reporter Lori Fullbright: "Did she explain that? How she out without the baby?

Cpl. Kraft: "She said she forgot she was sleeping with the child."

She forgot.

Police say the person who acted most responsibly and courageously that night was Carabelle's 12-year-old cousin who was watching TV in the other end of the house. They say the 12-year-old smelled the smoke and did everything to try to get people out of the house safely, just couldn't get to Carabelle's room in time.

Police say they're now waiting on the fire marshals report to see the cause of this fire and the autopsy to see the cause of Carabelle's death. Once they have those two things, they say they'll have a lot better idea of how the case goes forward.