Abstract: On November 24, 2008, a crew of seven employees from two companies were setting 80-foot trusses, to install a new roof system on an existing building. The truss system was supported by a steel column and beam system that was erected inside the building walls. Four employees were working among the trusses; one on each top plate and two in the web. Other employees were outside the building. At approximately 1:30 p.m., the 73 trusses, that had been set by the team, collapsed and fell to the building floor. A 50-year-old, English-speaking male worker from one company, Employee #1, had been working on the exterior top plate on the south side of the structure. Employee #1 fell approximately 15 feet, onto concrete, sustaining multiple fractures and head trauma. He was pronounced dead at 5:29 p.m., at St. Mary's Hospital in Decatur, Illinois. An English-speaking male worker from the second company, Employee #2, had been working in the truss webbing. Employee #2 fell with the trusses, and his foot was fractured. Another employee, who was on the exterior top plate on the north side of the building, was not injured. According to data collected from a weather station located approximately 5.6 miles from the construction site, the temperature ranged from 35 degrees F to 47 degrees F, and average temperature was 41 degrees F. Average wind-speed was 13.2 mph, and maximum wind speed was 25 mph. There were 0.03 inches of precipitation.