An 8-year-old boy was killed and two younger boys were injured Sunday night when the car in which they were riding ran off the highway and rolled over, State Police said.

The driver, Brian Gilton, 26, of Napoleonville, and the three boys, none of whom were restrained, all were thrown from the 2008 Chevrolet Impala after it hit a culvert and utility pole and overturned, troopers said.

Jaeden Holliday, of Napoleonville, was declared dead at the scene Sunday by the Assumption Parish Coroner’s Office, said Trooper Evan Harrell, a State Police spokesman.

The northbound Impala had gone off the right side of La. 1 near Howard Lane shortly before 9 p.m., troopers said.

Gilton was taken to Our Lady of the Lake Regional Medical Center with moderate injuries. The two children, who are 4 and 5 years old, were taken to Thibodaux Regional Medical Center with minor injuries, police said.

Citing State Police policy Monday, Harrell would not identify the two injured children but said the 5-year-old was Gilton’s son. Holliday and the unidentified 4-year-old were Gilton’s girlfriend’s children, Harrell said.

Impairment is suspected as a factor in the crash, troopers said. A sample of Gilton’s blood was submitted to the State Police Crime Lab and results are pending.