K Vinay Kumar of Kodambakkam, a Class 10 boy, was riding pillion on the two-wheeler driven by his elder sister K Varsha (22), a private firm employee.

The duo was riding to Poonamallee to visit a property their father had recently bought.

When they were on the Vandalur-Minjur ORR, Varsha applied the brake to prevent collision with another bike from the opposite direction.

In the impact, Vinay was thrown off and a truck plying towards Poonamallee ran over him. Poonamallee Traffic police sent the body for post mortem and booked truck driver for rash driving and causing death by negligence.