Law-enforcement officials say they will likely never know what caused an accident that killed a pair of married team drivers in Kansas earlier this year.

Truckdrivers Brad and Brenda Umholtz of DeSoto, KS, were killed June 24 when their tractor-trailer went over the side of the Kansas River bridge in the small town east of the Kansas City metropolitan area.

When officers arrived at the scene at 8:20 p.m. June 24, they found the cab lying on the driver’s side in the river, 65 feet below the bridge surface. Deputies said the truck appeared to be headed south on the bridge, which carries Wyandotte Street from rural Leavenworth County on the north side into DeSoto and Johnson County on the south.

The vehicle crossed the center line, hitting a guard rail on the opposite side of the street and falling into the river.

The Umholtzes, who were both in their 40s, were team drivers for Gainey Transportation Service Inc., Grand Rapids, MI.

At the time, investigators were unable to find a cause. Early reports that another car on the bridge may have been involved were ruled out. Lt. John Resman of the Johnson County Sheriff’s Office confirmed at that time that many of the obvious possible causes had also been ruled out.

“There’s no hidden health issues and we can’t find anything wrong with the truck,” he told Land Line.

Deputy Tom Erickson of the Johnson County Sheriff’s Department told Land Line Dec. 2 that nearly a half-year after the accident, investigators had still not found a cause.

“We just don’t know,” Erickson said, “and probably never will.”

--by Mark H. Reddig, associate editor

Mark Reddig can be reached at mark_reddig@landlinemag.com.