The incident occurred around 2 a.m. when the 35-year-old Smriti building in Mumbra town, some 40 km from the Maharashtra capital Mumbai, came crashing down, catching the sleeping occupants unaware.
A three-month-old infant and a seven-year-old boy were killed instantaneously while at least 22 people were rescued till Friday morning. The deceased infant girl has been identified as Mahek Muddasar Punjabi, police said.
Thane police commissioner KP Raghuvanshi said, "Rescue operations are the top priority. Investigation into the collapse will soon begin."
The injured, including some seriously hurt in the mishap, have been admitted to Kalsekar Hospital, CSMH and Civil Hospital in the city, the police added.
According to some reports, the building had been served an eviction notice some time ago by the civic authorities but the occupants failed to pay any heed.
Since hte incident happened in the dead of the night, bodies of victims were found together and not scattered.
Around 70 National Disaster Response Force personnel from Mumbai and 50 from Pune arrived at the site at 4.30 am. They were equipped with victim-locating cameras, air-lifting bags and bridging units.
On June 10, a four-storey building collapsed at Mahim in Central Mumbai in which ten people were killed and six injured. Prior to this, a building crashed on April 4 at Shil-Phata near Mumbra in Thane district which claimed as many as 74 lives and left over 60 injured.
(With inputs from a correspondent)