Investigators have doubts whether a teenage baby sitter who was supposed to be watching five children killed in a row house fire really exists.

Witnesses and neighbors are providing information that "has a tendency to cast doubt" on the baby sitter's existence, Pittsburgh police spokeswoman Diane Richard said.

"Legally, and in all fairness, we will continue the investigation so we can completely rule that out," she said.

The blaze, reported at about 1:20 a.m. Tuesday, began when children playing with matches set fire to furnishings in the living room of the three-story house in the city's Larimer neighborhood, officials said. The five children, who were found in an adjoining bedroom, died from smoke inhalation and carbon monoxide poisoning.

Authorities said they were told the children were left in the care of a 17-year-old baby sitter and investigators were given two similar-sounding names for the girl. Police haven't located her and police Chief Nate Harper called reports of the baby sitter "unsubstantiated."

"The community, the residents out there are stating they know of no one by that name nor do they have anyone that fits the description that the one mother gave," Harper told KDKA-TV.

The calls police are receiving are from longtime Larimer residents, Harper said.

One of the mothers, Shakita Mangham, 25, has hired an attorney, who declined to comment on the investigation.

"I can tell you she's very distraught," attorney James Ecker said Wednesday. "I spent quite a bit of time with her last night. She's just beside herself. She's making arrangements for the funeral."

Three of Mangham's children -- Daekia Holyfield, 7; Cedano Holyfield, 4; Dezekiah Holyfield, 3 -- died in the fire, as did two other children, Azquel Rankin, 5, and Andre Rankin, 6.

Police said the Holyfield children lived in the house and the Rankins were visiting; Ecker, however, would not say where Mangham lived.

Police have interviewed the two mothers and further interviews will be held after the funerals.

"What we are trying to do is give the mothers the time to grieve and breathe so they can bury their children," Richard said.

Investigators have said they don't know where the two women were at the time of the fire, but neither was at the house.

Police Chief Nate Harper said any charges, if warranted, would be filed after the funerals. No one has been arrested.

The fire destroyed the row house and another similar vacant building next door.

About two dozen candles dripping wax onto the asphalt stood among stuffed animals, balloons and other items near the house Wednesday. A wooden cross lay on the steps near a piece of burned debris and a greeting card. Across the street, someone taped two teddy bears and bouquets of flowers on a utility pole.

Visitation for the Rankin children will be 2 to 8 p.m. Friday at the House of Law Funeral Home, 9406 Frankstown Road, Penn Hills. Funeral plans were incomplete.

Visitation for the Holyfield children will be 4 to 8 p.m. Friday at Samuel E. Coston Funeral Home, 427 Lincoln Ave., Pittsburgh. The funeral is at 11 a.m. Saturday at Mount Ararat Baptist Church, 271 Paulson Ave., Pittsburgh.