Employees were setting trusses while on a scaffold. The injured employee was holding one end of a truss in place on the wall as employees pulled on the other end of the truss to set their side. The end of the truss near the injured employee fell. He stepped back and fell approximately 5'5" from the scaffold to the concrete floor. The injured employee sustained lacerations to the face, mouth, nose, and skull as well as fractures to multiple ribs, orbital bones, the scapula and the clavicle.