Kolkata: A four-year-old boy, Rudrangsh Sain, was severely injured after he was hit by a private car while trying to cross the road at the Karunamoyee Road-Motilal Gupta Road crossing at Jorapukur on Sunday evening.Sain was first admitted to SSKM trauma centre with multiple injuries, after which he was shifted to CMRI. Doctors said they might need to amputate the boy's left big toe. The driver of the car has been arrested. tnn