India, May 28 -- Monday's unprecedented downpour put to test the Aqua Line of Mumbai metro, where 1.1 million litres of water accumulated in its last station - the Acharya Atre Chowk (AAC) - which was only partially opened to public. There are six entry-exit gates to the station, of which two are open for public; four are under-construction. The heavy rain led to one of the under-construction gates flooding, leading to services to AAC being suspended.

The weight of the rainwater in the pit led to its collapse, flooding the station premises below. The temporary protective concrete retaining wall around it also failed to withstand the force of water. Officials from the Mumbai Metro Rail Corporation Limited (MMRCL) said the reason behind su...