Abstract: At approximately 11:30 a.m. on December 11, 2007, Employee #1 had accessed a mezzanine area to evaluate roof joist trusses for rated capacity and to ensure that the trusses were in good undamaged condition to withstand additional load of solar panels. There was not a guard rail on the south side of the mezzanine area. Employee #1 was walking across the mezzanine area, 9-ft 4-in. by 11-ft 4-in., when he tripped on an unknown object protruding from the floor. When Employee #1 tripped he fell at a 45-degree angle and fell through a "T" bar suspended ceiling. Employee #1 fell 11 ft onto a tile-over-concrete floor into the room below. Employee #1 sustained bilateral fracture on his wrists and was hospitalized.