In the narrow lanes of Vivek Vihar in East Delhi, where buildings are packed tightly enough to share both light and shadows, the early hours of Sunday were broken by screams.

From the first-floor balcony of the home where he has lived since 1984, Gurdeep Singh Gill watched the fire begin around 3.30 am. It was a flicker on the second floor of a neighbouring building which, within minutes, turned into something else entirely.

“There was no space for people to get out,” Gill said hours later, standing outside the four-storey, seven-year-old building where the tragedy had struck.

Most of the eight flats in the building are owned rather than rented.…