WATERLOO, Iowa (KCRG-TV9) -- The Waterloo Police Department says the fire was caused by accelerants.
The Waterloo Fire Rescue Fire Marshal submitted the evidence from the fire to the Iowa State Crime Lab, which determined an accelerant was involved in the fire.
The investigation of the fire is ongoing.
Waterloo Fire officials have released the names of the two people who died in a house fire on Sunday.
Officials identified the deceased as Jaykwon Sallis, 9, and his mother, Ashley Smith, 32.