The mishap occurred in Sahkar Nagar area of the city.
Rescue efforts were on. The cause of the collapse of the four-story building, which stood on the Taljai hillock, was not known yet, officials said.
Mumbai Roundup: 9 incidents that took place this week
Photos: Ajay Devgn, Parineeti, Tabu at 'Golmaal Again' trailer launch
Photos: Dipika Pallikal Karthik oozes oomph in bikinis and sarees
Photos: Kareena Kapoor Khan's grand birthday bash
Photos: 'Dangal' girls Sanya Malhotra, Fatima Sana Shaikh's dinner outing