Cpl. Jeff Hust told the El Dorado News-Times that prisoners began screaming, "Boss! Boss!" and that another guard grabbed the wheel but overcorrected. The van struck a culvert and went airborne, rolling twice before stopping.
Shawn Talbot, 29, of Ladysmith, Wis., and Walter Ridley, 47, of Clarendon died at the scene.
Seven inmates and two guards were in the van, which was on its way to Little Rock. Both guards were wearing seat belts, while the inmates were unsecured in the back of the van.
U.S. Extradition Service, based in Austin, Texas, transports prisoners and inmates under contract with law enforcement agencies. Bill Brees, a spokesman for the company, declined to comment.