KANSAS CITY, Kan. (AP) — Two maintenance workers at a Kansas water park where a boy was decapitated have been indicted in the case.

The indictments unsealed Wednesday charge David Hughes and John Zalsman with obstruction of justice. Both men pleaded not guilty Wednesday in Wyandotte County Court.

Hughes was maintenance supervisor at the Schlitterbahn water park in Kansas City, Kansas, and Zalsman was on the maintenance staff.

Ten-year-old Caleb Schwab was killed while riding the 17-story Verruckt waterslide in August 2016.

The indictment involves whether a brake mat meant to slow the rafts on the Verruckt was repaired after it fell off days before Caleb was killed.

The men allegedly told Kansas Bureau of Investigation agents the brake mat never existed but the indictment says a video showed it had been on the ride.