A 6-year-old rural northeast Nebraska boy has died after an all-terrain vehicle accident.

The Sioux City, Iowa, Journal reported that the accident occurred just before 11 a.m. Saturday on a farm northwest of Hartington in Cedar County. Authorities said the boy was operating the ATV when it went over an embankment and flipped on top of him.

Authorities did not release the boy’s name. They said he was taken to a hospital in Yankton, South Dakota, about 25 miles to the northwest of Hartington. He was pronounced dead there.

The accident remains under investigation. Hartington has about 1,500 residents and is 60 miles northwest of Sioux City, Iowa.