Fire was reported in a home on East Julian Street around 2:50 a.m., San Jose Fire Capt. Barry Stallard said.
A preliminary investigation revealed that the two residents of the home, a man and his adult son, left a fire in the fireplace before going to bed and it eventually spread to the rest of the home.
Both residents escaped the blaze without injury.
The fire was contained just after 5 a.m. but has not been declared under control.