Five people, including four members of a family, were mowed down by a speeding dumper truck early Friday in southwest Delhi's Najafgarh area, police said.
The dead have been identified as Ashok (30), his wife Kiran (27), his sons Ishant (5) and Dev (2) and one Jawahar Singh (93), they said.
While Ashok and his family were walking on the roadside to take a bus to visit a temple in Gurgaon, Mr Singh was out for his morning walk, the police said.
After hitting the victims, the truck crashed into vehicles parked by the roadside, they said.
A CCTV footage of the incident went viral on social media. In the video, the family of four is seen walking on the road near the parked cars. Ashok was carrying his younger son in his arms while his elder son was walking with his mother when the truck mowed them down.
"Information regarding the incident was received at 5.19 am at Thana Road police station. Ashok, Kiran and Ishant were found dead at the spot. Ashok's younger son Dev and Singh were sent to the Vikas Hospital," Deputy Commissioner of Police (Dwarka) Santosh Kumar Meena said.
Mr Singh and Dev died during treatment at the Safdurjung Hospital, he said.
The driver, who has been identified as Rajesh (35), was arrested from the spot, he added.
Five vehicles parked at the spot were damaged in the accident caused by the truck driver's rash and negligent driving, the police said.
The driver is undergoing a medical examination to ascertain if he was under the influence of alcohol or drugs at the time of the incident. He told police that he fell asleep at the wheel and lost control of the vehicle, they said.
A case under relevant sections of the Indian Penal Code (IPC) has been registered at Najafgarh police station, the police said.
The bodies have been sent to the Rao Tularam Memorial Hospital for a post-mortem, they said.
Mr Singh's grandson Rakesh Yadav said his grandfather went for a morning walk every day.
"I was sleeping when the accident took place. The neighbours informed us about it. We reached the hospital and found him dead," Mr Yadav said.
Mr Ashok worked as a security guard at the Vikas Hospital.
One of his family members said when he stepped out of the house, he saw that there had been an accident.
"An elderly man was lying on road and was rushed to the hospital. Later, I came to know that the children who had been hit by the truck were from our family. Ashok and his family were going to Sheetla Devi Mata temple in Gurgaon," he said.