PHILADELPHIA — Investigators in Philadelphia are trying to determine whether a 5-year-old started a fire that tore through a Philadelphia rowhouse.

The Philadelphia District Attorney's Office told CNN that an investigation is underway to find out whether a 5-year-old playing with a lighter under a tree could have sparked the fire.

The fire killed eight children and four adults.

The fire department originally said that the home's smoke alarms were not operational. However, CBS News reports that the Philadelphia Housing Authority, which owns the home, said 13 detectors were working during an inspection in May 2021.

Officials said 26 people had been staying in the rowhouse which contained two separate apartments.