Abstract: At approximately 6:30 a.m. on July 30, 2009, two masonry employees were working from a three-tier scaffold of a 4-ft high mason scaffold frames. The scaffold was 16 ft to the top platform. The scaffold was set up as a Mobile scaffold. The scaffold wheels were set up on two different levels. The building side was set on the porch area and the outside wheels were set on the second-from-the-top step. The wheel casters on the second-from-the-top step were set up on an array of bridging, two 4-in. by 4-in. by 16-ft posts, one- 2-in. by 10-in. by 16-ft scaffold plank, and a piece of 0.5-in. to 1-in. plywood. This bridging was not adjoined to prevent the potential of the bridging shifting. The employees were 12 ft above the porch level and 16 ft above the bottom of the stairway. The scaffold fell over. Employee #1 suffered a fractured tibia, broken ankle and rib. Employee #2 suffered a head injury. Both employees were hospitalized.