Abstract: At about 12:00 p.m. on January 26, 2006, Employee #1 was placing foam insulation into gaps in the framing at a condominium complex, where overhead joists pass from one residence into the adjacent unit. The foam material he was using was semi-liquid and applied like caulking material. In an area of the unit where gaps were located above a stairwell of the framed building, Employee #1 was using a 6-ft ladder to reach the gaps and apply the foam. The gaps he was filling were 8 ft above the second floor landing and more than 3 ft across the width of the stairwell. The employee stepped off the ladder onto a 2-by 4 fire block located between studs, and the fire block was not capable of supporting his weight. It collapsed. Employee #1 fell through and into the stairwell, causing a broken femur below the hip. He was hospitalized for several days.