Angry locals set fire to the bus after the incident and the vehcile was completely gutted, additional superintendent of police Tarun Haldar said.
The incident took place when the two alighted from the bus from the front door and were crushed to death by its rear wheels at Digberia here, he said.
The driver and grandma and grandson run-ver and killed by a bus while alighting.
The driver and the conductor of the bus are absconding since the incident, Haldar added.