CHICAGO – How, how, how? The question weighs on investigators as they work to determine what led to a Chicago house fire that killed 10 apparently unaccompanied children who had gathered for a slumber party at a West Side home.

Illinois authorities are investigating allegations of neglect, officials said Tuesday, but provided little additional detail — adding to a litany of questions about what started the fire and why the children weren’t able to get out.

Eight bodies were discovered Sunday after firefighters put out the fire. Two more victims, both 14, later died at John H. Stroger Jr. Hospital, said Natalia Derevyanny, a Cook County Bureau of Administration spokeswoman.

The fire started on the second floor of a coach house in Chicago’s Little Village neighborhood, fire officials said. Those same officials said there were no smoke detectors in the home, but Chicago Mayor Rahm Emanuel told reporters there were no functioning smoke detectors in the home.

Meanwhile, the building owner and his attorney have told local media the home did have smoke detectors.

The first floor of the building was vacant, and the second floor, where the children were found, was a home.

In an editorial lamenting the lack of answers surrounding the blaze, the Chicago Sun-Times quoted a fire official saying that it appears the kids could have escaped had they been alerted to the danger.

“From what we could see, they would have had a clear path out if they had been alerted early enough,” fire department spokesman Larry Langford said.

On Monday, Chicago fire officials passed out smoke detectors and fire safety information in the neighborhood.

As for why so many children were left alone in the home, a family member told CNN affiliate WGN the children were at the house for a sleepover and that his mother had been with the children earlier.

“My mom went to go drop off my little sister to her grandmother’s and by the time she was over there, I guess the house just started on fire,” said Marcos Contreras, who lost several siblings in the blaze.

A neglect investigation was opened after fire officials said there were no adults in the home, Illinois Department of Children and Family Services spokesperson Alissandra Calderon said in an email.

Questions have been raised about the state of the property. The building, a coach house, sits behind the main house, a three-story brownstone. Building records show that code enforcement officials have cited issues with both the main house and coach house since 2007, but there is no indication a code violation led to the fire.

The Chicago Fire Department said in a midday Wednesday tweet that the cause of the fire had yet to be determined.

“Engineering analysis pending on an electrical device unrelated to earlier violations,” the tweet said, adding that the Office of Fire Investigations was still awaiting reports from other agencies, including the Bureau of Alcohol, Tobacco, Firearms and Explosives.

More people might have died if not for a woman who smelled the fire and started knocking on doors and ringing doorbells to wake people up, Chicago Fire Commissioner Jose Santiago said.

Firefighters forced entry through a locked door into the small two-bedroom apartment, Langford said.

“Kids were just laying about,” he said.

It appears that none of the children tried to escape the blaze and that they likely died of smoke inhalation, he said.

Firefighters initially mistook several children for adults because they were covered in soot, making it difficult to determine their ages, Langford said. Firefighters went by body size, and some children had facial hair and looked older, he said.

The victims were part of at least two families, Langford said.

Officials have released the names of eight victims: 3-month-old Amaya Almaraz; Ariel Garcia, 5; Giovanni Monarrez, 10; Xavier Contreras, 11; Nathan Contreras, 13; Victor Mendoza, 16; Cesar Contreras, 14; and Adrian Hernandez, 14.