At least 20 people were killed and 21 others injured when part of a five-story building collapsed after heavy monsoon rains in downtown Mumbai, police said Wednesday.
"There could be more people trapped under the debris," said police officer Dheeraj Chauhan, adding that torrential rains were hampering rescue efforts.
Police said 11 people died in the wreckage while nine others who were critically injured died later in hospitals.
The building was in a crowded residential neighborhood with narrow lanes, making it difficult for rescue workers to provide medical treatment at the site, Chauhan said.
"There are 100 such buildings in Mumbai, where anything can happen in the monsoon," police officer K.L. Prasad told Reuters from Mumbai.
"Today's accident is an example and was waiting to happen."
Firefighters struggled along with volunteers to sift through mounds of concrete beams and smashed wooden furniture.
Police estimate the dilapidated building was around 65 years old.
Heavy monsoon rainfall and shoddy building construction are often blamed for building collapses in Mumbai.