(CBS) — An apartment fire in Kankakee last week that killed two young boys was arson, police said Monday.

Kankakee Police say that they are talking to a suspect who they believe might have started the fire in the apartment building in the 800 block of West Station St. last Wednesday.

The Kankakee County state’s attorney’s office could file charges in the near future.

Two-year-old Ju’shuan Watson and four-year-old Justice Stewart were airlifited to hospitals in Chicago.

Watson was pronounced dead at Loyola University Medical Center in Maywood Sunday afternoon. Stewart died on Friday at Comer Children’s Hospital.

Three adult residents of the building were injured.