In Kolkata, Prime Minister Narendra Modi officially opened India's first underwater metro station. Additionally, he lay the cornerstone for several connection projects totaling Rs. 15,400 crores.

The nation's first underwater transit tunnel is located in the Howrah Maidan-Esplanade segment of the Kolkata Metro. With a depth of 30 metres, the Howrah metro station is the deepest in all of India.

The IT centre Salt Lake Sector V is connected to a number of localities by the 4.8 km stretch of the East-West Metro track that runs between Howrah Maidan and Esplanade.

The East-West Metro corridor from Howrah Maidan to Esplanade was constructed at an estimated cost of Rs 4,965 crore, according to the Metro Railway.

The tunnel under the river is one of 10.8 kilometres of the East-West Metro circuit that is subterranean, according to news agency. The complete itinerary consists of 12 stations.