Miami County, according to authorities.
The boy’s name and age were not released. The accident was reported around 3:30 p.m. at 335th Street and Rockville Road, the Miami County Sheriff’s Office reported.
According to initial reports, Jacob Masterson, 19, of Paola, was traveling north and collided with a westbound vehicle driven by Stacy Adams, 45, of Louisburg.
Adams was taken by helicopter to a Kansas City hospital, where she was listed in critical condition. Her two grandsons were in the back seat. An 8-year-old was stable condition at a Kansas City hospital. His younger brother died at the scene.
Masterson sustained minor injuries and was taken to a Kansas City hospital. Authorities said the adults and children were wearing seat belts.
Investigators said the accident happened on gravel roads that did not have traffic signs. It remains under investigation.