REVERE-A boy about five years old suffered a serious head injury Tuesday in a car accident on Thornton Street, police said.The unidentified boy was placed into in a medically induced coma at a local hospital, Police Capt. Michael Murphy said.Police and firefighters responded to 64 Thornton St. shortly before 5 p.m. after the boy collided with a car operated by Alfio T. Berardi of Wakefield, according to police. As of Thursday night, Berardi had not been cited.Police Chief Terence Reardon said Thursday the boy is expected to survive. The chief also said it appears the boy might have run into the car.”It appears he may have ran into a passing car,” Reardon said. “He banged off it and landed on his head? and fractured his skull.”Murphy said an investigation into the accident is ongoing by the Revere Police Department’s Traffic Division, the State Police Reconstruction Unit and members of the Suffolk County C-Pac Unit, which typically investigates serious or fatal accidents.