Abstract: On June 21, 2010, an employee, a heavy equipment mechanic, was removing a 0.75-in. bolt from the track link plate on a Caterpillar D6R. The bolt head had been sheared off and the stem remained in the well of the track link. The employee began the removal process on Friday, where he made several attempts to weld another extracting nipple onto the headless bolt; WD-40 had been applied to the headless bolt to aide in the removal. On the following Monday, the employee returned to work and began working on removing the bolt. There were no witnesses but nearby coworkers heard a loud "POP", looked over and saw a small cloud of smoke and saw that the employee had fallon over. The employee had a heating torch still in his hands and operational, he had a hole in his chin where the bolt stem entered, killing him instantly. It was assumed that the employee was applying heat to the area with the torch causing it to expand, forcefully pushing the headless bolt out of the hole.