A nine-year-old boy, Prasath, died on the spot after a call taxi in which he was travelling along with seven others collided with a sewage truck in Uthandi on East Coast Road on Sunday.
Five persons were injured in the incident. Two children, including a two-year-old girl, escaped.
Police said the accident occurred around 10.45 a.m. near the toll plaza on ECR when the sewage truck heading towards Chennai attempted to overtake another vehicle and rammed into the van going to Mamallapuram.
Prasath, a Class V student and a resident of Alapakkam, died on the spot.
Selvaraj (50), driver and owner of the van, his wife Shanti (41), Rajasekar (11) and Anitha (20), suffered injuries and were admitted to a private hospital in Perumbakkam. Harini (2) and Gunasekar (13) escaped unhurt.
All passengers and the driver of the car were from Gangai Amman Kovil Street in Alapakkam, police said.
The driver of the truck fled from the scene after the accident.
Adyar traffic investigations have registered a case and are investigating.