Investigators say it happened around 9:30 Wednesday night on Olive and Cedar.
Numerous eyewitnesses say someone threw something into the kitchen but fire officials won't confirm the foul play.
Meanwhile the lady who lives in the apartment was next door when the fire broke out. When she realized her home was on fire it was too late.
A man living with the woman was inside the bedroom sleeping when the fire broke out. He was treated and released at the scene.
The damage from the fire is estimated at $65-thosuand dollars.