Southbound Interstate 29 was backed up at Platte City, Missouri, for a triple fatality crash involving multiple vehicles Friday afternoon.

The Missouri State Highway Patrol said the accident involved four vehicles at Missouri Highway 92 at Platte City, near the Tracy, Missouri, exit at mile marker 18. Traffic was backed up to at least mile marker 25 in the southbound lanes for several hours but the scene was clear by 4:30 p.m.

The patrol’s Troop A office in Lee’s Summit, Missouri, released the victims’ identities. The fatalities were listed as 75-year-old Carol E. Wehking of Lancaster, Kansas; her daughter, 44-year-old Lisa R. Wilson of Effingham, Kansas; and her husband, 54-year-old James W. Wilson, also of Effingham. All were traveling together in a 2004 GMC Envoy sport-utility vehicle, with James Wilson as the driver.

John F. Klapp, 71, of Correctionville, Iowa, who drove a 2002 Dodge Ram 3500 pickup involved in the crash, was seriously injured, according to the patrol. A passenger, 40-year-old Christopher J. Klapp, also of Correctionville, had minor injuries. Both were taken to North Kansas City Hospital for treatment.

Of all the accident victims, the patrol said John Klapp was the only one not wearing a seat belt.

The patrol said the accident happened at 12:24 p.m., in the southbound lanes of I-29 at Missouri Highway 92. The SUV driven by James Wilson and a 1979 Kenworth tractor-trailer unit driven by John D. Toth, 53, of Tonganoxie, Kansas, were both stopped in the right lane of I-29 due to congestion from a construction zone ahead of them.

The pickup Klapp was driving southbound on the interstate struck Wilson’s GMC, which in turn struck the rear of the tractor-trailer and caused it to travel into the left lane and strike the side of a 2004 Ford Econoline E250 van.

The pickup traveled off the right side of the road into the grass and landed on its wheels, facing southwest. The SUV overturned and landed on the right shoulder on its top, facing northwest. The tractor-trailer and the van came to a controlled rest on the right shoulder.

The Missouri Department of Transportation reported that some passing vehicles were driving on the shoulder of the southbound lanes.

Motorists who managed to make it past the accident scene encountered another delay due to a traffic crash farther south at southbound I-29 and North Oak Trafficway, near Barry Road. Delays were expected at that location until 5 p.m.

The crash near North Oak Trafficway was reported before the triple fatal accident a few miles north at the Tracy exit.

The Platte County Sheriff’s Department assisted at the scene.

Dave Hon can be reached at david.hon@newspressnow.com.

Follow him on Twitter: @NPNowHon.