The accident took place in front of the Kirti Nagar metro station, police said.
Three persons were killed and one injured early Sunday as the car they were travelling in rammed a tractor on Shadipur flyover in west Delhi's Moti Nagar, police said.
The accident took place after the car hit the tractor from the rear near the Kirti Nagar metro station around 1.30 am, they said.
Some passersby pulled out the victims, who were childhood friends, from the mangled car and sent them to Acharaya Shree Bhikshu Hospital in Moti Nagar, a senior police officer said.
Deputy Commissioner of Police (West) Deepak Purohit said Rajesh Sharma, 32, Tarun Gupta, 42, and Charandeep Singh, 38, all residents of Pandav Nagar, were declared brought dead by doctors at the hospital.
Parveen Singh, 38, a resident of Jhilmil, is under treatment and was not fit for recording a statement, the DCP said.
He said the accident took place on a road from Moti Nagar to Patel Nagar on the Shadipur flyover.
Rajesh Sharma's brother-in-law Girja Shankar Joshi said the four had gone for a dinner Saturday in Punjabi Bagh area when the incident happened.
"They were childhood friends. I spoke to Parveen Singh's wife who said he was in a deep trauma. I could not speak to her for long as we were busy in cremation," Girja Shankar Joshi said.
Rajesh Sharma used to work with a courier company at Mahipalpur and is survived by his wife and two daughters.
Charandeep Singh used to work in a media organisation and is survived by his wife, a daughter and a son, while Tarun Gupta used to run a computer shop at his residence and is survived by his wife and a daughter, police said.
Parveen Singh is the owner of the car, but he was not driving it at the time of the incident, they said.
Police said an FIR has been registered and the bodies have been shifted to the DDU Hospital for autopsy and further investigation is underway.