Immediately after the incident, the lorry driver jumped out and escaped from the spot. The mishap caused a traffic snarl on the road in the morning rush hour.
The victim has been identified as Pranesh of Taramani. The accident occurred at around 8.20 am when the child’s grandfather, Gopal and grandmother Uma were taking Pranesh on their two-wheeler from Ennore to Taramani.
According to police, the tanker was driven rashly by the driver and he lost control and hit Gopal’s vehicle from behind. In the impact, all three fell from the vehicle. While the boy was run over by the lorry, killing him on the spot, his grandparents escaped with minor injuries.
The tanker also hit a few other two-wheelers on the road before ramming into a traffic sign post, police said.
Passers-by and traffic personnel on duty sent the child and other injured persons to Government Royapettah Hospital for treatment.
Adyar traffic investigation police later said the driver of the tanker, Sameer has been nabbed.