SOUTH SACRAMENTO --
It's been less than three weeks since a South Sacramento house caught fire, killing two children asleep upstairs.
Now the Sac City Fire Department has determined flames started downstairs in the living room.
"The cause of the fire has not been determined, we were not able to rule out either candles or electrical," said Chris Harvey, spokesman for the Sac City Fire Department.
Harvey said pinpointing what sparked the fire is a challenge because it burned so intensely, leaving items charred and damaged.
"I talked to the coroner. They were asleep. They were asleep," said the victim's mother, LaDonna Lee, immediately after the fire.
Eleven-year-old Ire and 6-year-old Israel were killed.
A 12-year-old boy escaped the flames through an upstairs window and a firefighter suffered burns to the cheek. Both of them survived.
The Fire Department has responded to at least two other fires at the home, once in 2012 and once in 2013. Firefighters say both times they found candles inside the home.
"A common theme in all three fires was that there were candles in the home. That doesn't mean the cause of the fire was candles, it's that afterwards while sifting through the rubble, investigators were able to determine there was candle residue," Harvey said.
Although investigators consider the fire accidental, they say this tragedy is a reminder to take extra steps to prevent house fires.
"Everyone needs to make sure they have a working smoke detector in their home. Everyone needs to make sure they plan and practice an escape plan with every member of their family," Harvey said.
Harvey adds that people should never leave candles burning or unattended at home.