The fire was reported around 1:00 Monday afternoon inside the Glasgow Court development on the 200 block of Ingram Street in Bear, Delaware.
Fire officials say the blaze started in the living room and was caused by combustible items placed too close to a space heater.
One firefighter suffered minor injuries while battling the blaze. He was treated and released from Christiana Hospital.
A number of pets perished in the fire and while none of the occupants were home at the time, the family of five was displaced due to the damage.
The family is being assisted by the American Red Cross.
