Abstract: At 10:00 a.m. on December 29, 2022, an employee was using spanner wrench to tighten the bit he had installed into the chuck of the Kasuga milling machine. The chuck of the milling machine was free spinning and not allowing the employee to tighten the bit properly. As the employee held the spanner wrench with his right hand; he reached up to apply the brake lever with his left hand. At that instant the machine unexpectedly started, and the chuck spun rapidly with the spanner wrench still on it. The spanner wrench was thrown from the spinning chuck and struck the employee handle first approximately in the center of his chest creating a puncture that ultimately resulted in his death.