Firefighters said the narrow roads and steep terrain in the neighborhood made it difficult to get to the three-story home.
They say the fire started in the back of the house and spread rapidly.
"I think the aggressive nature of the attack saved the balance of the structure and prevented it from spreading to neighboring houses," said L.A. City Fire Assistant Chief Ralph Terrazas.
It took about an hour to knock down the flames. The cause is still unknown.