Residents said the fire moved fast.
"We were scared 'cause we thought that our house was going to get on fire," said neighbor Jasmine Juarez.
There were bars on every window, making it even more difficult for fire crews. Firefighters cut holes in the roof and were able to knock down the fire quickly.
"After further investigation, we discovered cause of fire was due to a space heater that was placed on the floor with quite a few combustibles around it," said Capt. Albert Luna of the Los Angeles City Fire Department.
Fire investigators said the family was very lucky. A family of four lived in the home, but they were not at home at the time. No one was injured in the fire.
Firefighters said space heaters can be very dangerous. Officials reminded the public when using portable space heaters to make sure the area around it is clear and do not leave them unattended.