At least 18 people have died after an overpass, under construction in the city of Kolkata, collapsed. The incident was the latest in a series of deadly construction collapses in India.
Police officials said the metal-and-cement structure came down on Thursday in the state capital of West Bengal. The flyover passed close to houses and shops in an extremely congested area in the northern part of the Indian metropolis.
Local media showed images of firefighters and residents trying to rescue the dozens of people trapped under the wreckage. The number of victims is expected to rise.
A 140-tonne crane brought to the scene of the incident was unable to lift a concrete slab under which many people were feared trapped, including passengers in a minibus.
"We heard a noise and got scared. Yesterday it was welded. The bridge collapsed. I think at least 150 people are under the debris," an eye-witness Ramesh Kejriwal told Indian news agency, ANI.
Derek O'Brien, a lawmaker and spokesman for the ruling Trinamool Congress Party in West Bengal state said in a tweet that the incident was a "monumental tragedy."
The accident on Thursday was just the latest in a string of deadly construction collapses in India - some of which have highlighted the country's poor building standards.
India's huge demand for housing, roads and other infrastructure often results in cost-cutting and a lack of safety inspections.