JOHNSON COUNTY — A former Brown County man was killed in a rollover accident on Nineveh Road early Monday morning.

Just after 6 a.m., a vehicle crossed the center line, went off the road and flipped, landing upside down in a ditch along Nineveh Road, just south of State Road 252.

The driver, Randall R. Albertson, 51, was ejected and found about 30 yards away, according to a news release from the Johnson County Sheriff’s Office. A medical helicopter was called to the scene, but Albertson died before being transported, the release said.

Investigators are trying to determine what caused Albertson’s vehicle to go off the road, Johnson County Sheriff’s Office Chief Deputy Col. Randy Werden said.

Another driver told police that Albertson had passed them but then lost sight of his vehicle when the road became hilly. Shortly after, the other driver saw headlights and knew that Albertson’s vehicle was flipping, Werden said. But the other driver did not see what had led to the accident, Werden said.

Investigators will inspect Albertson’s vehicle for any issues, such as a damaged tire that could have caused him to go off the road, Werden said.

They will also look for a black box, or a device that records data about the vehicle, such as the speed the vehicle was traveling, he said. But since Albertson’s vehicle was older — a 1988 Oldsmobile — it may not have had a black box, he said.