The steady drizzle, the occasional downpour and the widespread disruption assumed dangerous proportions on Day III, with a state of alert being declared in several parts of Waterworld Calcutta.

At least 50,000 people were marooned in pockets submerged under knee-deep water on Friday. The worst-hit areas were Basundhara Park, Sonali Park, Kashthadanga, Kshudiram Pally and Ananda Nagar of Behala, where 2,500 residents were being shifted.

If 4,000 families were marooned in Chowbhaga and Topsia, around 1,500 families were stranded in Baishnabghata and Bansdroni. The Port area, too, was afloat.