ENDERLIN (AP) - An Ottertail, Minn., man was killed on the job in this southeastern North Dakota town when he fell about 20 feet down an elevator shaft.

Terry Helsene, 33, was pronounced dead at the scene Monday morning, the Ransom County sheriff's office said Thursday.

Helsene was working with CS DuBois Construction Inc. out of Fargo, helping install an elevator in Enderlin's city auditorium, said Bruce Beelman, area director in Bismarck for the Occupational Safety and Health Administration.

Beelman said a preliminary investigation indicates that Helsene stepped from a ladder to a guardrail over the opening of the elevator shaft, trying to gain access to a scaffold.

"He stepped on the guardrail and the guardrail broke, and he lost his balance and fell through the opening," Beelman said of the preliminary investigation.