A 62-year-old man died in a building collapse in north Delhi's Sabji Mandi area, taking the death toll in rain-related incidents in the national capital to three, with as many injured in separate incidents across the city, officials said on Thursday.

Heavy rainfall unleashed chaos in Delhi on Wednesday evening, inundating large parts of the city, while key stretches were choked with unending traffic and people left stranded.

According to a police officer, the deceased, identified as Anil Kumar Gupta, was inside the building when it collapsed at 8.30 pm. He succumbed to his injuries at Saint Stephens Hospital, the officer added.

A 22-year-old woman, Tanuja, and her three-year-old son, Priyansh, who had gone to a weekly market in east Delhi's Ghazipur area, drowned after they slipped into a waterlogged drain on Wednesday night. The incident took place around 8 pm near the Khoda Colony area, where the roadside drain was under-construction, the officials said.

The duo were brought out with the help of divers and cranes and taken to Lal Bahadur Shastri Hospital, where doctors declared them brought dead, the police officer said.

Till 7 am, the Delhi Police had received 2,945 calls of traffic jam, 127 calls of waterlogging, 27 calls of building collapse and 50 calls of falling of trees, the officials said.

A woman was injured and a car was damaged in a wall collapse in south Delhi's Defence Colony around 9.30 pm on Wednesday, the police officer said.

Two other people were injured after a portion of a house wall collapsed in northeast Delhi's Shastri Park area at 7.30 pm on Wednesday, the officer said.

The police, however, did not reveal any details about the injured.

Five cars were also damaged when a wall of a school collapsed in central Delhi's Daryaganj on Wednesday night, the officer said.

In another incident, at least six cars were damaged in a wall collapse incident in southwest Delhi's Vasant Kunj area, he added.

The torrential downpour prompted the weather office to include Delhi in its list of 'areas of concern' in the National Flash Flood Guidance Bulletin.

The department advised people to remain indoors, secure windows and doors, and refrain from unnecessary travel.

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