On the intervening night of July 18 and 19, Delhi received heavy rainfall spell leaving several areas water logged. In the afternoon of July 19, a video went viral on social media showing collapse of houses along Sen Nursing Nala at ITO, Delhi.
The incident happened due to a breach in right bank of storm water drain at the back of WHO building reportedly damaging about 12 houses of Anna Nagar, a fifty years old slum area located along the left bank of the drain.
The breach was indeed of unprecedented scale in the national capital. The impact was so powerful that there was apparently a landslip on left bank swallowing away a house in gushing current. The water current started rushing in opposite direction from downstream part of the drain.
There was wide circulation of the horrific video which invited loads of comments where some social media users even titled it Kedar Nath like disaster of Delhi. However possible specific reasons for the breach are not known.
SANDRP visited the location on July 25, 2020 and also talked with some MCD officials, shopkeepers and local residents to find out what exactly had happened.
One of the MCD official said that there was burst in pipeline running across the drain at the site. Some shopkeepers revealed that the drain was flooded dangerously. But the local people were quite clear that it was a result of basement related construction work at the WHO building.
They alleged that there was a tree standing on the embankment bordering WHO building. The basement work had exposed and loosened earth around it. The cumulative impact of rain, wind, flood in drain and basement work led to collapse of the tree which developed into a massive breach in no time flooding the entire basement and causing landslip on left bank that ultimately damaged the houses.
The incident has led to the left bank of drain prone to more slips. The breached location is plugged with hundreds of earth bags. The vulnerable residents have been shifted to relief camp set up near Indraprastha Metro Station.
The Google Earth images reveal that WHO building has been built on approximately 5,000 square meter area on the right side of Sen Nursing Nala. The embankment is the only structure that separates WHO building and the drain for about 120 meters of length which was covered by thick tree canopy. But now large part of right bank embankment is stripped of the trees during construction of the WHO building.

All these details suggest that a possible reason behind the breach in drain was WHO building construction work. However, the relevant authorities have not made or set up any official inquiry into the incident to learn lessons and avoid reoccurring of such avoidable tragedies.

By way of abundant caution, areas immediately adjoining drains should not be populated, this also applies to large government, institutional and private buildings. One hopes that the city administration would investigate the incident to avoid repeat of such episodes.

Bhim Singh Rawat (bhim.sandrp@gmail.com)