Abstract: At approximately 11:00 a.m. on October 6, 2004, Employee #1 was working on a new wood frame residential construction, hand nailing second story floor joists in place to the framed walls at a height of 10 feet above grade when he began to feel dizzy. He attempted to call out for help but was unable to speak. Employee #1 lost motor coordination and fell through the 2 ft by 4 ft floor joists, which were spaced 24 inches apart on center. He hit his head on the concrete slab below and suffered a laceration to the head. The initial illness that Employee #1 suffered and that led him to fall was not work-related.