Indiana state labor department officials are investigating an unusual equipment-related accident at an overpass project in Elkhart County, Ind., on Jan. 18 in which pile or pipe-driving rig or its hammer struck a crew member in the head and killed him.

The employee, 31-year-old Michael Aaron Knotts, was pronounced dead at the site by firefighters called to the accident, according to a report by the county coroner.

Knotts, a member of carpenters' Local 1485 in La Porte, Ind., was employed by Rieth-Riley Construction, a major paving and highway contractor in Goshen, Ind. Company officials could not be reached for comment.

Local media reports stated that Knotts was guiding placement of a pipe section when the rig hammer or rig struck him in the head.

According to the coroner's report, Knotts was "harnessed inside a cage directing a new pipe" into the rig when "for an unknown reason the device holding the hammer" failed and the hammer dropped and struck him. The coroner said firefighters removed Knotts from the cage and brought him to ground level.

A funeral home website described Knotts as having an "adventurous spirit" that "led him to recent success" when he achieved journey-level status."Michael loved working for Reith-Riley, always striving to reach the next level," the website stated. 

The accident is the second fatality involving a Rieth-Riley employee within the past year.

In May, a dump truck operated by a subcontractor at a work zone in Lafayette, Ind., killed 53-year-old Dale Thomas. According to state labor officials, he was placing sample plates when the dump truck operator backed over him, inflicting fatal injuries. State officials proposed a penalty against Rieth-Riley of $7,000 for exposing Thomas to the crushing hazard.

It is not known if Rieth-Riley is contesting the penalty.

This article was update Feb. 4 to reflect that pipe, not pile, was being driven.