A resident of the 2000 block of Zoria Circle, off of Hostetter Road near Interstate Highway 680, called 911 at 6:37 a.m. to report smelling smoke and seeing sparks coming from an electrical outlet, San Jose fire Capt. Mary Gutierrez said.
Around that time, two other 911 calls came in from motorists who were passing by and noticed black smoke coming from vents on the second story of the two-story home, she said.
Firefighters arrived in about five minutes and entered the house.
"Once they got into the attic space, there was fire in the attic," Gutierrez said.
They extinguished the flames by 7 a.m. but remained at the home making sure the fire was completely out.
The one-alarm blaze burned through the roof and caused serious damage to the attic, and there was also damage to upstairs bedrooms where firefighters had to pull down the ceilings to access the flames, Gutierrez said.
The cause of the fire has not yet been determined.
The American Red Cross has been called to assist the displaced residents.