Live video on local station KNBC-TV showed the fire was still active as of 7 p.m. Pacific time.
More than 230 firefighters were responding to the scene, FOX 11 of Los Angeles reported.
In this screen grab from video provided by Sean Miura, flames from an explosion are seen Saturday, May 16, 2020, in Los Angeles. (Sean Miura via AP)
Numerous stretchers were lined up in the street outside the building and helicopter crews were seen nearby, apparently planning to transport the injured to hospitals.
Firefighters were called to a Boyd Street address around 6:30 p.m. local time and the blaze spread to some surrounding buildings, KTLA-TV of Los Angeles reported.
This is a developing story. Check back for updates.