A Vicksburg man was among four people killed in two weekend traffic accidents occurring on the Natchez Trace and Interstate 20.

Christopher H. Koestler, 46, of Vicksburg, was one of three people killed Friday in a three-vehicle accident involving a pickup truck and two motorcycles that occurred about 5:55 p.m. on the Natchez Trace in Claiborne County south of the Rocky Springs Campground, according to information from the National Park Service.

Claiborne County Coroner J.W. Mallet said Koestler, a passenger in the truck, and the motorcycle riders, Jan P. Elliott, 66, of Covington, Ky., and Joseph E. Park, 65, of Lakeside Park, Ky., were pronounced dead at the scene.

Koestler’s cousin, also named Chris, the driver of the truck, was flown to University of Mississippi Medical Center, where he was in good condition, a hospital spokesman said.

The cause of the accident remains under investigation.

About 2 a.m. Saturday, a Belzoni woman was killed near Flowers while she was sitting on the shoulder of the eastbound lanes of Interstate 20 while waiting for a tire to be changed on the SUV in which she was a passenger, Mississippi Highway Patrol spokesman Trooper Eric Henry said.

He said Ashley Dancer, 26, was killed when an eastbound 18-wheeler struck the rear of a Ford Explorer that had pulled over to help the GMC Yukon in which Dancer was a passenger. The impact from the semi hitting the Explorer knocked the SUV into Dancer, killing her.

Warren County Coroner Doug Huskey said she was pronounced dead at the scene. An autopsy was ordered.

Another person, Jamia Ransome, 27, of Greenville, who Henry said was sitting on the tailgate of the Yukon, was injured and taken to U MMC, where she was in good condition, a hospital spokesman said.

The other occupants of the Yukon, who were standing outside the SUV, and the driver of the Explorer, who was sitting in the SUV when it was hit, were not injured. They were not identified. The driver of the truck operated by Haul America Trucking LLC of Conyers, Ga., was also injured and taken to UMMC. He was not identified.

The accident occurred about 2 a.m. According to MHP reports, the Yukon had pulled off on the shoulder of the highway with a flat tire, and the driver of the Explorer pulled over to help.

While the tire was being changed, the 18-wheeler veered off the roadway and struck the Explorer, knocking it into the Yukon. Dancer was sitting between the Yukon and the Explorer.

The driver of the 18-wheeler told troopers another 18-wheeler passing him forced his tractor-trailer off the roadway, causing it to hit the rear of the Explorer.

The accident is under investigation by MHP Crash Team.