The fire happened on Thursday just after 6 p.m. Crews responded to the 1500 block of Palisades Drive. A photojournalist with the Palisadian-Post captured drone video of firefighters on the roof.
The Los Angeles Fire Department says there was light smoke in the building and it took them about an hour to knock it down.
Arson units responded to the scene.
The cause of the fire remains unknown. In a social media post, Pratt claimed this was the work of arsonists.
The investigation is ongoing.