The suspects broke into one business, then knocked holes through the walls to gain entrance to the others.
"It's just drywall, so it's easy to go through," said Brandon Bello, whose parents own B.K.A. Fashion, a clothing shop that has been in the American Garment Center building for 10 years.
Bello estimates his parents' store lost about $8,000 in the burglary. Neighboring shop owner Im Kang says she's out about $10,000 in theft and damage.
"All the cash is gone," she said. "Computer stuff and the personal identity of the corporations, tax report and all the documents - they steal everything."
The building manager says as many as 16 businesses were hit. Store after store was ransacked. The thieves tried making off with a new flat screen TV, but when it wouldn't fit through a hole in one of the walls, they broke it.
Los Angeles burglaries are becoming more common.
The latest Los Angeles Police Department crime stats show burglaries in L.A.'s Central District are up 17% year over year through March. Throughout the entire city, they're up 11%.
Bello says LAPD doesn't seem to be moving very quickly on this case.
"They told us that the best thing they could do is that the detective won't be here until possibly tomorrow," he said. "They don't even know if that's guaranteed."