CASPER (WNE) — A 5-year-old boy has died from injuries he sustained when a car he was traveling in collided with a semi-truck southwest of Casper last week, the Wyoming Highway Patrol said Thursday.

The child, who was not identified, was in the backseat of a Honda Pilot that struck the semi-truck on June 9 near Pathfinder Reservoir.

The crash occurred at around 8:20 p.m. as the semi-truck was heading east on Wyoming 220. The Honda, driven by Sierra M. White, 23, of Evansville, had been stopped on Pathfinder Road. As the truck passed by the intersection, the Honda accelerated forward and into the semi’s path, the highway patrol said.

The semi-truck struck the driver’s side of the Honda, and both vehicles overturned, the patrol reported.

White, the 5-year-old boy, a 4-year-old child and a passenger — Catherine Brummett, 27, of Evansville — were all taken to Wyoming Medical Center with injuries. The 5-year-old boy died shortly after arriving.

The highway patrol report did not describe the extent of the other’s injuries.

The truck’s driver, 62-year-old Lusk resident Howard Lorenzen, was also injured and taken to Wyoming Medical Center.

The highway patrol says it is investigating driver inattention and cell phone use as possible factors that contributed to the crash.

Forty people have died so far this year on Wyoming roads. That’s roughly how many have died in the past two years.