Abstract: At 12:40 p.m. on December 9, 2021, an employee worked to cut away some concrete and PVC pipe to make enough clearance to meet Americans with Disabilities Act compliance. The employee used a portable vertical grinder (Milwaukee M18 FUEL ? Inch Die Grinder) to make the cuts using a Lennox three-inch diamond cut off wheel. The employee worked from a kneeling position with a rag stuffed down a nearby pipe to prevent material from falling into it. As the employee cut the pipe, the wheel caught onto the rag and the grinder vibrated out of the employee's hands. The cut off wheel struck the employee's knee before it automatically shut down. The employee was taken to the hospital to treat a laceration to the knee. The employee was not hospitalized.