The incident happened around 9.30 p.m. at Vijay Nagar slums in the Antop Hill area.
A portion of the wall and the upper floor collapsed partially and some sections were hanging precariously.
The Mumbai Fire Brigade rushed a team there and pulled out two persons from the debris. They were rushed to the Sion Hospital where they were declared dead, the BMC said.
The deceased were identified as Shobhadevi Maurya, 45 and Zakirunnissa Shaikh, 50. The work of clearing the rubble is underway and there are no details of any more victims in the tragedy.