Sen. Dick Durban, D-Ill., asked the Transportation Department’s Inspector General to review the Federal Motor Carrier Safety Administration’s investigative practices.

The agency dropped the ball on an investigation of a carrier that later was involved in a fatal crash, Durbin said in his April 9 letter to IG Calvin Scovel.

He cited a Chicago Tribune story that said the agency ordered but never followed up on an investigation of DND International, which had a history of safety violations.

The agency did not start its investigation until after a DND driver was involved in a crash that killed a tollway worker and injured a state trooper, Durbin said.

The driver had been on the road for more than 30 hours with little or no sleep, Durbin said in his release.

He asked Scovel to review the agency’s practices to ensure that carriers that have been flagged are investigated in a timely way.