A 4-year-old boy is dead after an ATV accident Saturday morning.It happened around 10am off Cutler Road in East Machias.Game Wardens said Troy Denison, 37, was riding with his son and nephew, both 8 years old, on the ATV.Wardens believe one of the boys accidentally hit the accelerator. The ATV then hit an embankment and rolled over. After the accident, the riders realized they rolled over onto Wesley Keeton, 4, who was playing near by. Keeton, who was the drivers nephew and one of the boys brothers, was pronounced dead at the scene. Denison and the other riders sustained minor injuries. The accident remains under investigation.