Abstract: On June 5, 2017, Employees #1 and #2 were participating in a firefighting exercise at a local elementary school. Both employees were in training, although Employee#2 was more junior than Employee #1. The exercise involved accessing the roof of the elementary school by way of a 35 foot extension ladder, which consisted of three sections. During the exercise, Employee #1 was the third person to climb the ladder to the roof, followed by Employee #1. As Employee #2 was ascending the ladder and readjusted his footing to access the school roof, the upper extension of the ladder collapsed. Employee #2 rode down with the second section of the ladder until it seated into the first section, at which point he lost his grip, fell to the ground, and lost consciousness. Employee #2 fell an approximate 28.7 feet. Employee #1, who had reached for Employee #2, struck his left arm against the cap of the parapet and fractured his left forearm. His right arm sustained bruising as well. The incident investigation attributed the incident to the enclosed pawls of the ladder's second extension were not easily visible at an estimated 20 foot in height. It was possible that the pawls were not fully set (latched) into the ladder rung and slipped from the vibrations of the firefighters ascending the ladder.