Five people, including a woman pulled out by bystanders, were rescued after a morning blaze at an apartment building on Carling Avenue.
The fire broke out around 6:45 a.m. Friday.
Ottawa Paramedics had to treat eight people and transport four to hospital.
The woman who was pulled from the apartment where the fire originated was treated for smoke inhalation and second degree burns to her lower body.
Other people were treated for smoke inhalation and carbon monoxide toxicity.
Ottawa Fire said late Friday the cause of the blaze was deemed accidental. Damage estimates were not immediately available.
