A four-storey building named Gitanjali collapsed in Saibaba Nagar in Borivali west at 12.34 pm on Friday.
The building had been vacated as it was declared dilapidated.
WATCH | Four-storey building collapses in Borivali west
The fire brigade is now at the site of the collapse to ensure no one is trapped in the debris.
At least eight fire engines, two rescue vans, one quick response vehicle and three ambulances have been deployed to the site.
No injuries have been reported so far.