Police investigations into the collapse of a five-storey PG building in Delhi's Satya Niketan reveal that three truckloads of debris were used to level the basement, and a crucial wall was removed on the ground floor shortly before the incident. Seven people died and five were injured. The building owner, labour contractor, and a PG operator have been arrested, while another operator is absconding. Concerns about building safety and unauthorised construction in the area have been raised.