The fire happened at a large Church of Jesus Christ of Latter-day Saints facility in the 15500 block of Saticoy Street at about 2:15 a.m., according to an LAFD alert from spokesperson Brian Humphrey.
Los Angeles firefighters said they discovered the scene after smelling smoke in the area as they were driving by from another blaze. That allowed them to get to the scene very quickly, officials said.
Upon arrival, crews found flames coming out of what they described as a classroom, located in the back of the structure.
Crews were able to contain the fire in its initial spot and prevent damage in the structure's chapel, officials said. The blaze was declared a knockdown after about an hour.
"The fire was blowing out. There was about zero visibility inside, very hot conditions, and they were able to, fortunately, keep the flames confined," said LAFD Public Information Officer Erik Scott. "Again, if it wasn't for firefighters being able to find this so quickly, work with our friends at the LAPD, this could have been much worse."
No injuries were reported as a result of the fire.
Arson investigators were at the scene to help determine the cause.