A father-son duo, who was awarded the contract to allegedly construct an additional floor illegally on a single-storey house, died after the building collapsed in North East Delhi’s Harsh Vihar on Sunday evening, said police. The owner of the house has been arrested, police said.The deceased were identified as Chanderpal, 60, and his son Vijay Kumar, 33, both of whom were inside the building when it came down. Police said that the additional floor was being built without permission.“Preliminary inspection revealed that the ground floor of an old building, which reportedly also housed a godown, collapsed along with a structure on its first floor. The property is reportedly owned by one Manoj Kumar,” police officers said.On Monday, Vijay’s wife Anita recalled the last time she talked to him. Anita said she had told him around an hour before the incident that dinner was ready and that she was waiting for him.“When I called him around 6:30-7 pm, his number was not reachable. I called his brother and asked him to check on him,” said Anita, a mother of two.A resident of Gali number 14, situated merely blocks away from the building that collapsed, Anita said that when her brother-in-law reached the spot, the building had already collapsed. Chanderpal’s bike was still parked nearby.Vijay had started the construction only on Sunday morning. The house was built on an area of about 200 sq yards, inside a narrow lane swarmed with buildings, most of which house shops.Story continues below this adThe ground floor of the building had a concrete slab, while the structure above it had a lighter slab with iron rods. It has been learnt that workers were trying to replace the iron slab with a concrete one, but the base of the building wasn’t able to bear the load of the same.The Municipal Corporation of Delhi (MCD), in a statement, said: “As per the local enquiry and the circumstances of the incident, it appears that during the execution of the work, while replacing the T-iron and stone slab roofing with an RCC slab, the rear portion of the first-floor structure reportedly collapsed and fell onto the roof of the ground floor. Consequently, the roof of the ground floor also collapsed, resulting in the collapse of the affected portion of the building. The front portion remains in its previous condition, with the ground floor having an RCC slab and the first floor having a T-iron and stone slab, at the same level.”According to Delhi Fire Services (DFS) officials, a call regarding the collapse in Harsh Vihar’s Milan Garden was received around 6:46 pm.Officials of the National Disaster Response Force (NDRF) and the Delhi Disaster Management Authority (DDMA) were among personnel deployed at the site for rescue operations, which ended by Monday morning, police said.Story continues below this adEarlier, on October 7, a pregnant woman and two children were killed after a four-storey building collapsed in Northeast Delhi’s New Seemapuri.On September 6, a five-storey building in South West Delhi’s Satya Niketan that was being operated as a paying guest accommodation collapsed, killing seven people.(Edited by Ditiya Saha)