The fire was reported at 7:48 p.m. in the 4800 block of South Alameda Street, according to Margaret Stewart of the Los Angeles Fire Department.
The roof collapsed over an 80,000-square-foot building that adjoined four different buildings, Stewart said.
Thick plumes of smokes visible from miles out filled the sky as firefighters fought the flames with the help from aerial ladder trucks.
A fire also erupted at the location on Tuesday, Stewart said.
The cause of the Thanksgiving blaze was under investigation.
"With our investigators on scene, they're gonna be able to start to determine what the circumstances were around this fire," said LAFD Capt. Cody Weireter.
Firefighters worked to put out hot spots late into the night.
City News Service contributed to this report.