Abstract: On May 5, 2004, an employee nailed wooden blocks between studs near ceiling level using a "Hitachi" pneumatic nail gun. When he fired a nail into a block, through a stud, the recoil of the gun caused it to jump back, hit the adjoining stud, and bounce forward again. The employee was still holding the trigger in the firing position, and the gun fired again. It sent a nail into his right hand, and about 0.375 inch into his thumb. The employee then removed the nail, cleaned the wound at the jobsite, and went back to work. Two days later, at another jobsite, the foreman told the employee that his wound looked infected and sent him to a nearby hospital where he was admitted and stayed for two days until the infection was under control.