The collapse occurred on Saturday during the renovation of the building, and the casualties were all construction workers, Reuters reported.
An investigation into the cause is going on, it said.
The accident in the eastern city follows several similar incidents recently, including the collapse of a gym in heavy snow in the northeast province of Heilongjiang last week, which killed three.
In July, 11 people were killed when the roof of a school gym caved in during intense rain, also in Heilongjiang province, drawing criticism from the media. Authorities said construction materials illegally stacked on the roof may have caused the collapse.
AMK/PR