About 3:20 a.m. firefighters rushed to a home on Rock Spring Drive, near I-40 and Luther Road.
One of the occupants called 911 and said his house was on fire.
The trailer home was 75% engulfed when crews arrived.
Everyone escaped safety, except the family dog.
One person was treated for smoke inhalation.
Investigators say the fire may have started on the porch by a lit cigarette.