CHICAGO (CBS)–No working fire alarms were found in the home where eight children died in the Little Village neighborhood, where a fire broke out during a family sleepover early Sunday morning.

Safety concerns about the building on the 2200 block of South Sacramento were raised in 2015, a city spokesperson said. The landlords of the building, Merced and Maria Guitierrez, were cited for not having smoke detectors on the second floor of the back house. They are due in court next month to address the violations from June.

Amaya Almaraz, Ariel Garcia, Xavier Contreras, Nathan Contreras, Victor Mendoza. (CBS)

The cause of the fire is undetermined, but the blaze appears to have broken out on a rear porch, authorities said.

“We lost eight people to a fire and that’s unheard of in the city of Chicago,” said Annette Nance Holt, Deputy District Chief for the Chicago Fire Department. “We haven’t lost this many people–I can’t even count back to when we lost this many lives.”

An examination of city records shows six building code violation cases concerning the property since 2008.

A group of firefighters went door-to-door for about three blocks Monday morning near the apartment building where the children died, passing out fire safety information and free smoke detectors to families in need. They also offered to install smoke detectors for the elderly for free. Anyone who needs a smoke detector also can call their alderman to pick one up.

Relatives said the children who died were having a sleepover. They ranged in age from 3 months to 16 years, according to their families.

The oldest victim, 16-year-old Victor Mendoza, was visiting his friends for a sleepover. His mother said he was a good student.

The youngest victim, Amaya Almaraz, was only 3 months old.

Also killed were 5-year-old Ariel Garcia, 11-year-old Xavier Contreras, 13-year-old Nathan Contreras, 3-year-old Alanni Ayala, 5-year-old Gialanni Ayala, and 10-year-old Giovanni Ayala.

A Go Fund Me account has been set up for the family:

CBS 2’s Vince Gerasole and Suzanne Le Mignot contributed to this story. 

Vince Gerasole