Abstract: At approximately 9:45 a.m. on July 11, 2011, Employee #1, a Lab Technician of Aerotek, Incorporated, was working alone in the "physical lab" processing the calcine for laboratory sampling. Employee #1 was operating the Morse Brothers Machinery Company, Roll Crusher Model GM-6219, with an Identifier Number of RR69-48. Employee #1 was attempting to clean the "excess, bigger lumps" from the machine that were stuck and thought that the machine was off. The machine is equipped with a hinged interlock guard that does not stop the rollers immediately. The machine has a 6 to 7 second time lapse when the interlock is released. Employee #1 reached in and his right thumb was amputated to the first knuckle. Employee #1 was transported to John Muir Medical Center, Walnut Creek, CA, where he had surgery to reattach his right thumb.