On September 5, 2006, a 30-year-old construction laborer (the victim) was fatally injured when he fell through a floor opening to a concrete floor approximately 10 feet, 10 inches below. The victim had spent the majority of his work shift cutting plywood sheathing and handing it up to coworkers who were sheathing the roof. He was working from the second floor of a two-story, single family home under construction where he and other workers had completed most, but not all, of the subfloor (plywood sheathing secured over floor joists) on previous workdays. They had left a floor area open in an attic space where a walk-in closet was to be constructed later. At the end of the shift, the victim's lead worker asked two workers to complete the second story subfloor in the attic space. One of these workers joined the roofers to lay roofer's felt. The other co-worker joined the victim and together, they cut two sheets of plywood sheathing and placed them over the joists in the open area in the attic space. They were not wearing fall protection. The co-worker reported that he was looking down at the sheets of unsecured plywood sheathing trying to make the pieces fit into an opening that was not square and when he looked up the victim was gone. The victim had apparently stepped onto a piece of the unsecured plywood sheathing that covered part of the floor opening, and when the plywood sheathing pivoted on the floor joist, he fell through the opening. The victim's co-worker immediately phoned their employer who was working off-site. The victim's employer then called the general contractor's field manager, who was working on-site, and the field manager called 911. Emergency medical services (EMS) arrived within minutes and immediately transported the victim to an area hospital. The victim was pronounced dead in the emergency room. NIOSH investigators concluded that, to help prevent similar occurrences, employers should: 1. ensure that all employees are provided with and use appropriate fall protection when exposed to fall hazards; 2. ensure through employee training and job-site inspection that correct construction procedures, such as use of appropriate fasteners, are followed during all phases of construction; 3. develop, implement, and enforce a comprehensive, written fall protection program that, at a minimum, complies with applicable OSHA fall prevention standards; 4. assign a competent person to inspect the worksite before work begins to identify fall hazards and to determine the appropriate fall prevention systems for workers; 5. ensure that all employees are provided with training in the recognition and avoidance of fall hazards and the fall protection system they are to use in the workplace where fall hazards exist, in a language and at a literacy level that all workers can comprehend. Additionally, nail manufacturers should consider color coating the body and head of nails used in pneumatic nail guns so that a specific color corresponds to a specific nail size.