CHICAGO (AP) – A weekend Chicago apartment fire that authorities say was started by fireworks or other smoking materials has claimed its ninth victim.

The Cook County Medical Examiner’s Office says 14-year-old Cesar Contreras died Monday evening at a hospital. Another boy, also 14, remains hospitalized. Officials say that teen’s condition was too critical for investigators to interview him about what happened.

Fire Department spokesman Larry Langford said Monday that investigators learned children had set off fireworks on the porch in the past and that people had smoked cigarettes there.

The fire that happened before dawn Sunday killed seven children and two adults.

The Chicago Sun-Times reports that the city’s Buildings Department says the apartment building’s owner is due in court next month after being cited for two electrical violations. Investigators have ruled out electrical problems as the cause of the blaze.