The incident occurred at plot number 3 near Bombay City Hospital around 5 am, a civic official said.
Maharashtra chief minister Uddhav Thackeray held an emergency meeting on Thursday morning to review the situation.
The Marathwada region is also expected to receive widespread showers till Thursday and the rain intensity is likely to reduce subsequently, he said.
In 2005, RTI activist Anil Galgali had sought information on how many slums lay close to landslide-prone locations and the government plans to relocate them.
Due to heavy downpour in the western suburbs since Saturday night, rainwater entered inside the civic body's parking lot run by a private contractor.
The local train and road transport services, which were badly affected due to the torrential rains and water-logging on Sunday, were now running normal, they said.
At least 25 people died in rain-related incidents in Mumbai, with 17 casualties reported from Chembur alone in a wall collapse mishap on Sunday.
The inundation at the complex has affected water supply in most parts of the metropolis, the official added.
Mumbai: After wall collapse, two women stood on wooden ladder for two hours over fear of electrocution
The woman said she opened the door and managed to come out of the house with the help of a wooden stick.
PM Narendra Modi expressed anguish at the loss of lives caused by wall collapse incidents in Mumbai due to heavy rains.
Seventeen people died as a compound wall came crashing down on some houses located on a hillock after a landslide.
The rain fury reminded some Mumbaikars of the 24-hour rainfall figure of 944 mm on July 26, 2005.
Heavy rains lashed across Mumbai and its suburbs on Friday displacing hundreds of slum dwellers, flooding low-lying areas and disrupting the local train services.
Due to heavy rains and waterlogging the railway tracks were seen waterlogged and on the slow line near Kurla-Vidyavihar, trains are running 20-25 minutes late.
The incident took place in a residential society on Cama Lane in Ghatkopar West on Sunday morning, police said.