Five persons were rescued from the debris of the building in Kamathipura area of Grant Road, which caved in at around 2 PM, a Fire Brigade official said.
However, two of the injured succumbed to injures at J J Hospital and Nair Hospital, according to BMC Disaster Control Room officials.
The condition of the other injured is said to be critical.
Many people are still feared trapped under the rubble, the Fire Brigade official said, adding the structure housed a beer bar and a factory, among others.
Eight fire engines and three ambulances were pressed into rescue operation, the official said.
PTI