Gurugram, Feb. 25 -- A couple and their five-year-old son were killed, and their seven-year-old son was critically injured after their car rammed a concrete wall on the Delhi-Jaipur expressway in Nuh's Rozka Meo, police said on Tuesday. The crash took place around between 2 and 2.30pm on Sunday when the vehicle allegedly lost control while trying to avoid a stray dog, officers added. The deceased were identified as Naveen Kumar Soni, 40; his wife Madhuri Soni, 38; and their son Vihansh, police said. Their injured son, Krishan Soni, is undergoing treatment at a private hospital in Gurugram, they added. Vihansh succumbed en route to hospital and Naveen died late Monday night. While Madhuri succumbed during treatment on Sunday. According to police, the family had been living in Old Gurugram for the past seven years and were originally from Nainwa village in Bundi, Rajasthan. They said Naveen was a manager posted at Indian Bank's zonal office in Sector 32. A senior police official in Nuh said the family had travelled to Jaipur to attend the wedding of Naveen's brother-in-law. "They were returning to their Gurugram residence on Sunday when the crash took place between 2pm and 2.30pm on Sunday," he said. "After preliminary inquiry, it has come to light that Naveen, who was behind the wheel, had tried to avoid collision with a stray dog that had suddenly come on the Expressway about 2.5 km before Hilalpur toll plaza," he said. "The Maruti Suzuki Fronx veered off course, climbed onto the divider and rammed a concrete wall of an underpass which mangled the car beyond recognition and trapped the occupants inside," he added. Investigators said two commuters stopped and tried to help the injured couple, who could still talk. They used the couple's mobile phone to alert family members in Jaipur and tried to rescue them by pulling them out of the mangled vehicle but failed. A family member said the victims were taken to a private hospital in Gurugram's Sector 69 on Sohna Road. "Vihansh was dead due to head injuries by that time. Madhuri had started gasping due to facial and head injuries. She collapsed soon after, and doctors tried to resuscitate her but failed to," he said. He said Naveen was admitted there but later shifted to Fortis Hospital in Sector 44 as his condition worsened, where he died late Monday night. "Now, Krishna is the lone surviving member of the family. We are devastated by the incident," he said. Krishan Kumar, public relations officer of Nuh police, said the family has not suspected any foul play or involvement in any other vehicle. "An inquiry under section 194 of Bharatiya Nagarik Suraksha Sanhita was carried out on the basis of the family's statement at Rozka Meo police station in which they have denied involvement of any other vehicle in the crash," he said, adding that the bodies were handed over after autopsies....