Here are the top 10 developments in this big story
A team of the National Disaster Relief Force is helping with the rescue work. Senior police officers are at the spot to conduct the operations. NDRF initially said 10-12 were feared trapped under debris, but the police later clarified that was not the case.
Two of those killed are women and use to work at the GT Hospital, where 10 of the injured people have been shifted. Ten others have been moved to the St George hospital.
Maharashtra minister Vinod Tawde said, "The bridge wasn't in a bad condition, it required minor repairs for which work was underway. Why it was not closed until the work was completed - that will also be probed".
"Pained to hear about the FOB incident near TOI building in Mumbai. Spoke to BMC Commissioner and @MumbaiPolice officials and instructed to ensure speedy relief efforts in coordination with @RailMinIndia officials," Chief Minister Devendra Fadnavis tweeted.
The overbridge, built in 1984, connected the CST platform 1 at the north end of the railway station with B T Lane near the Times of India building. The traffic in the area has been affected. The police have asked commuters to use alternate routes.
Minor repairs had been carried out on the CST bridge six months ago as part of a safety audit ordered when another foot overbridge collapsed in Andheri last June. The audit had encompassed 445 bridges of the city.
"The bridge was of BMC (Brihanmumbai Municipal Corporation). However, we are extending all our supports to the victims. Railway doctors and personnel are cooperating with BMC in relief and rescue operations," news agency ANI quoted an official of the railways ministry as saying.
"We are deeply saddened by the news of the #MumbaiBridgeCollapse, our thoughts & prayers are with the families of those who lost their lives & we wish the injured a speedy recovery. We urge all Congress workers to help in any way they can," the Congress tweeted.
A 40-year-old bridge at the Andheri station had crumpled after heavy rains. Railway Minister Piyush Goyal had then said the bridge, built in 1971, had a "design flaw". Nine months before that, in 2017, 23 people were killed in a stampede at the Elphinstone Bridge.
The Chhatrapati Shivaji Maharaj Terminus is a UNESCO World Heritage Site and serves as the headquarters of the Central Railways.