"They were standing on the fifth floor balcony, which was being constructed illegally, when the ceiling fell on them. They plummeted to the ground floor and were buried under rubble," said an officer.
Neighbours informed the police who rushed to the spot, rescued the mother and child and took them to the Jag Pravesh Chandra Hospital from where they were subsequently referred to the Sushruta Trauma Centre after their condition deteriorated.
Police said they were still critical and undergoing treatment.
Investigation revealed that Shahnaz's husband, Aamir, had engaged a contractor for its renovation. They had temporarily moved to an adjacent building from where they would visit the under-construction building every day.
A case has been registered against the contractor at the New Usmanpur police station for the illegal construction.