A brush fire was initially reported at about 2:45 p.m. near the southbound 2 Freeway and Verdugo Road. The flames spread to the Church of Jesus Christ of Latter Day Saints in the 3900 block of Roderick Road.
Large flames devoured much of the roof and heavy smoke could be seen billowing from the church.
Flames were contained primarily to the attic and firefighters were working on defending the rest of the structure, said Margaret Stewart with Los Angeles Fire Department.
At least one firefighter was receiving treatment, but was in good condition, Stewart added.
The church has more than 400 members and the building is about 25 years old. No one was inside at the time of the fire.
PHOTOS: Flames devour roof of church in Glassell Park
DEVELOPING: We will add more details to this report as they become available.