Jream Jenkins died in the fire, WZTV reported. Her 23-month-old brother is listed in critical condition at an area hospital, the television station reported.
The other children, all siblings, are ages 6, 4, 2 and 1, according to WKRN. The two boys and two girls were taken to an area hospital, the television station reported.
A spokesman for the Nashville Fire Department said several people were trapped inside the burning apartment, WZTV reported. Passersby told police a 6-year-old boy ran out of the building and said his siblings were still inside, the television station reported.
Police said the two mothers returned to the apartment while first responders were at the scene, WZTV reported.
Nashville Fire Department spokesman Joseph Pleasant said arson detectives are part of the investigation, the Tennessean reported.
"The circumstances of the fire and the cause of the fire remain under investigation by the fire marshal's office," Aaron told the newspaper.