The fire broke out around 9:30 Saturday night at the home on Butler and Second in Downtown Fresno.
Firefighters say it started in the chimney area and spread from there.
All six family members made it out safely, but they were not allowed back in the home.
The Red Cross helped them find a place to spend the night.
About sixteen firefighters had the blaze contained by midnight.
Fire officials are estimating the damage at $40 thousand.