Abstract: At approximately 7:30 a.m. on June 4, 2003, an employee of Panelized Structures Inc. raised a stack of 45 plywood sheets, 4 ft by 8 ft by 0.5 in., along with 2-ft by 8-ft boards, and hangers, onto the top of the roof of building number 8, utilizing a fork lift. The employee went to the top of the roof via an extension ladder to unload the plywood sheets. As he pulled one plywood sheet off the stack and stepped backward, he fell 21 ft through a 2- ft by 8-ft roof opening down to the concrete floor, sustaining serious multiple fractures of his both feet and left elbow. He was hospitalized and treated for fractures.