At least 40-50 people are feared trapped under debris after a four-storey building collapsed in south Mumbai's crowded Dongri neighbourhood around 11:40 am Tuesday, reports NDTV.
Three large teams of the National Disaster Response Force (NDRF) are at the site, looking for survivors. The area, full of dilapidated buildings on narrow lanes, was also flooded in heavy rains in the past weeks.
Ambulances and fire trucks have arrived and are parked some distance away from the building as the lanes are too narrow for them to enter.
"We heard a loud noise. Everybody shouted, 'building is falling, building is falling'. I ran. It felt like a big earthquake," a teenager who saw the building fall told.
"This building must be 90-100 years old. I saw the bodies of some children. There were some seven-eight families in the building," another eyewitness told.
In videos of the rescue operation, NDRF personnel in their bright safety gear are seen trying to remove concrete blocks as they probe the openings amid the debris for signs of life.
The authorities said this was a "level 2" incident - while level 1 is the most serious under the system that measures the severity of a building collapse.
Crowds thronged about the narrow lanes - where it would be extremely difficult for heavy machines to reach - and formed a human chain to pass down with their bare hands small debris like wooden blocks and bricks towards the outer area of the neighbourhood.