Firefighters responded shortly before 7 a.m. to a blaze at a single-story commercial building in the 3700 block of Cahuenga Boulevard, near Lankershim Boulevard, according to the Los Angeles Fire Department.
"While the firefighters were en route, they were getting reports that there were people trapped inside," said LAFD Assistant Chief Patrick Butler. "That caused us to immediately go into search operations."
The flames in the 50-by-75-foot studio, called Top Notch Studios, were extinguished within 30 minutes.
"As you can see from the building, extremely challenging, in between other buildings," Butler said. "So we were able to make sure this fire did not spread and burn down the entire block."
Two men were pronounced dead at the scene; the three survivors were transported to hospitals. The victims were not immediately identified.
The people who managed to escape said there were no smoke alarms or fire extinguishers inside the building.
The cause of the incident was being investigated by the LAFD's Arson/Counter-Terrorism Section and the Los Angeles Police Department's Robbery-Homicide Division.