The Sacramento Fire Department says the fire that killed a six-year-old and an 11-year-old Dec. 1 was the third fire at that address in the last three years.
Investigators were unable to determine the cause of the fire that gutted a two-story home on Babette Way.
They say it was either faulty wiring or decorative candles.
Investigators say candles were in the home at the time of the other fires.
Chris Harvey is with the fire department. He says four adults were downstairs when the fire started and three children were upstairs.
"There was not a window on the second story that led out onto the roof, so the means of egress were either down the interior stairwell or out an open window and a drop to the ground level."
Harvey says the upstairs bedrooms had no fire ladders.
"Part of our investigation was discussing with the family members whether or not there had been an escape plan in place and it sounds as if they had not discussed an escape plan."
Adults in the home say they woke up because of a fire alarm.
Harvey says a 12-year-old boy upstairs survived. He hung onto a window sill and then dropped to the ground below.
The boy was treated for an injured ankle. He has also been offered counseling.
A firefighter was also injured fighting the fire.